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Still Struggling...



 
 
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  #91  
Old July 15th, 2008, 09:10 PM posted to microsoft.public.access.gettingstarted
BruceM[_2_]
external usenet poster
 
Posts: 1,763
Default Still Struggling...

I don't have much time to reply today, but I have noted a few things inline.

"Aria" wrote in message
...
I found the compile button. It was under commands so I added it to the
toolbar. Thanks.

I will take a look at your questions, but you will need to sort of start
over with your descriptions, as I have not been following very closely of
late. When you do so, list only the essential fields.


Not quite ready to list the table structures for this part yet...still
stinging from the last time when they were all wrong. I just basically
want
to think on post. Ask a few questions and have you weigh in on where I'm
going wrong. Are you Ok with that? I completely understand what you mean
as
far as having lost track. I have all my notes and posts and I still have
to
read up on what's going on and what transpired.

Questions unrelated to 2nd half of db:
1. When I input the programmng code for the AfterUpdate event, I input
cboStaff_Lookup. The line highlighted in yellow said, "Private Sub
cboStaff_Lookup_ AfterUpdate () Was I supposed to input that final
underscore
after Lookup?


If you select the combo box, open the Property Sheet (with the tabs for
Format, Data, etc.), select an event, click the three dots, click Code
Builder, and click OK the name of the control will be filled in for you in
the code window. If you type it yourself you need the underscore. I think
that is so there are no spaces in the procedure name.

2.Ever since this started taking off in earnest, I have often thought that
this db seems to be complicated; maybe that's just beginner's woe. I
don't
know because I don't have a point of reference. Both you and Beetle stated
in
your posts to each other in the beginning that it wasn't simple for a
first
app. My question is how did you know? We hadn't even really gotten into it
past the original 6 tables. How does one determine complexity?


There's no definitive answer for that, but anything that involves junction
tables is a lot to get your mind around if you are just starting. Before
long, if it hasn't already happened, the need for junction tables, and how
to use them, will be clear in your mind. In your case there were a number
of junction tables, and a situation that involved keys, locks, people to
whom the keys were issued, locations of the locks, campuses, and a number of
other entities, with a variety of relationships between the entities.

Hoping this is not too much for you in one post...

We know:
1. This is a staff database for a school setting.
2. We encompass 2 campuses.
3.Db emphasis is on keys because they have been problematic.
4. We have already suffered through a re-key of an entire campus,
including
the stadium, gyms and gates.
5. Many locations w/o a room #. (Ex. Auditorium, Stadium, Storage Rms.,
etc.)
6. Master keys allow general access for a single campus.
7. Master keys are unique, employee specific and their allocation is
severely restricted.
8. Storage, Stadium, Food Service and Gate Masters are location specific
*and* follow rule #7.
9. Wing masters will only open all rooms for a specific section of the
site.
10. Key assignments are based on job title, room assignment and
extracurricular duties.

Where we left off:
1. We had 4 tables relating to keys or location: tblRooms,
tblKeysEmployees
(junction), tblKeys and tblKeysRequests.


What became of tblLocks? If one lock may have several keys, locks are the
top level.

2. There was a lot of discussion involving home, personal cell, district
cell and room phone #s. The last decision was that home/personal cell is
part
of tblEmployees; district cell and room phone #s are part of tblphones.

Suggestions still on the table:
1. Create tblLocations to replace tblRooms.
2. Create tblLocks to define the relationsip between keys and locks. There
should be a 2 field PK involving Key ID and LocationID.
3. Create Master Key table to account for the special attributes of Master
Keys.
4. Create additional look-up tables: tblCampuses, tblWings and
tblLocationTypes.

If your eyes haven't glazed over... You don't have to answer today; I know
it's a lot.

Questions/Comments:
1.Decision--Unbeknowst to you and Beetle, I was going to use a natural key
for KeyID in tblKeys. Your statement about a possible re-key and our
history
of such finally made me realize that this was a *lousy* idea from the
beginning. I'm switching to autonumber.


There's nothing wrong with a natural key, depending on what it is. With a
surrogate key such as autonumber the main thing is that the record needs to
be unique for reasons apart from the autonumber field. If two records are
identical except for an artificial identifier then they are not really
unique. The autonumber is a convenience, but cannot by itself enforce what
is known as a unique constraint.


2. Master keys--This is a sub-type of key, correct? You can have one key
and
many masters or is it many sub-types (Gate, Stadium, etc.) But you can
also
have one specific master that has many keys assigned. While the master is
employee specific, it *is* essentially the same key that is assigned to
every
employee who has clearnace. It's just coded so we know in advance who we
gave
it to. This is a 1:M relationship? You can't have a M:M relationship with
sub-types can you? Either way it will have its own PK. This is where I'm
confusing myself and going around in circles.


I'll have to ponder this one later.


I'll stop here for now. Thanks!

--
Aria W.


"BruceM" wrote:

I think that Macros may be considered to be something other than code,
but
I'm not sure. If you use the wizard the code is added automatically.
You
can view it, but you may not know it was added. In any case, unless you
use
macros, which are rather limited, you pretty much need VBA code for
anything
other than a very simple database.
To find the Customize option I mentioned, open your database. In the
database window, click the Forms tab. Click View Code, or click the
Code
icon on the toolbar. What you see is the VBA editor. Right click a
blank
spot on the toolbar or menu bar. You should see Customize, probably as
the
last item on the list. There are of course other ways to open the VBA
editor, so choose another method if you prefer. The way you open it is
not
important (although I wouldn't try to customize while debugging).

I will take a look at your questions, but you will need to sort of start
over with your descriptions, as I have not been following very closely of
late. When you do so, list only the essential fields. For instance, for
tblEmployees:

EmployeeID (PK - Number)
LastName
FirstName
etc.

may be enough. For tblSiteEmps, list the PK/FK field, the relationship
type, and a few fields that will give the idea of how the table is used:

tblSiteEmps (1:1 tblEmployees)
EmpID (PK/FK)
Home Phone-txt
Address-txt
etc.

This is enough for our purposes. Give yourself a break from typing all
of
the details, unless for instance the fact there is a cell phone number is
relevant to the problem at hand, and make it easier for me or another
responder to read. Limit your description to a few typical fields, or to
fields that are part of your code or that are involved in relationships.


"Aria" wrote in message
...
You know I had never been to this section of my database before.
Originally,
I had no intention of putting in any programming code. I tried doing as
you
suggested but when I go to Customize...Options...I don't see what you
are
describing. What I see in the Options tab is Personalized Toolbar and
Menu
but it's greyed. The only button you can push is Reset my Usage Data
(?).
Maybe I'm in the wrong place.

I wanted to return to the 2nd half of the db. I still need to work on
tables
but I have questions (naturally!) Do you mind?
--
Aria W.


"BruceM" wrote:

I should have said 'Still in the VBA editor, click Debug Compile."
This
is in the menu bar, not in the Tools Options dialog. I like to
have
that
command readily available, so I added it to the toolbar. To do that,
right
click on the toolbar, click Customize, click the Options tab, click
Debug
on
the left, and drag Compile from the right side to the toolbar.

BTW, you could sort the row source for the Employee combo box by the
concatenated (LastFirst) field. If you sort on LastName you should
sort
on
FirstName next, in case two people have the same last name. You don't
need
to show the LastName and FirstName fields.

"Aria" wrote in message
...
Guess what? It works...it works! I'm trying real hard to hold it
together,
but I am so happy. sniff Thank you *so* much! OK, so let me tell
you
what
happened. I'm going to combine parts of both your posts.

Bruce M wrote:
If you view the SQL in datasheet view you will see that the first
column
is
EmpID. Column 1 should be the bound (hidden) column in
cboStaffLookup.
This statement:
rs.FindFirst "[EmpID] = " & Me.cboStaffLookup
means "Find the first record in the RecordsetClone in which EmpID is
the
same as EmpID in the combo box."

Beetle wrote:
A combo box will only display the first visible column in its
unexpanded
state, so in that case you would need to concantenate the names in
your
query as Bruce suggested. His example query might look like this in
design view;

Field: EmpID
Table:tblEmployees
Show: Yes (The box is checked).

Field:LastFirst:[LastName] & ", " & [FirstName]
Table:
Sort:
Show: Yes

Field: LastName
Table:tblEmployees
Sort: Ascending
Show: No

Aria writes:
It was the combination of both your posts that allowed me to follow
along
closely. You explained what was happening and then said this is what
it
will
look like.

Bruce M wrote:
Private Sub cboStaffLookup_AfterUpdate()

End Sub

The cursor should be blinking between those lines. Add the code.
After
you
enter:
Dim rs As Object
press the Enter key to go to a new line (or press it twice to create
some
space and make the code easier to read). Add:
Set rs = Me.RecordsetClone
Press the Enter key again, and add the next lines of code, pressing
the
Enter key after each one.

Scroll to the top of the code window and be sure the words Option
Explicit
are under Option Compare Database. Add them if they are not. If they
are
not, in the VBA editor click Tools Options. Click the Editor tab,
and
check the box Require Variable Declaration.
Still in the editor, click Debug Compile. This will highlight any
typos
and other such errors in the code.

Aria writes:
Step by step instructions...how could I ask for anything better than
that.
The Require Variable Declaration box wasn't checked. I didn't find
the
Debug
Compile box but it did have Auto Syntax Check box. When I ran it I
got
a
Compile error (Error 461). I used Help for this part. When I was
finished,
I
noticed that Private Sub cboStaff_Lookup_AfterUpdate () was
highlighted
in
yellow; highlighted in blue was cbo StaffLookup. I didn't notice the
underscore with cboStaff_Lookup before. That did it.

Bruce M wrote:
I don't know what is happening with the sort order, but let's not
get
too
many things cooking on a Friday afternoon.

lol Well, on my end it may be a little late for that. One more
thing...the
sort order is working as it should. I can't believe my book said it
could
be
done w/o code. I can't thank you both enough. Still trying to hold
it
together. Have a great weekend!
--

Aria W.


"Aria" wrote:

Something's not right here. tblEmployees should not have a field
for
TitleDescription. The only place the TitleDescription field
should
exist
is in tblTitles. Can you post your current structure for the
following
tables (hopefully I have the table names right)?

Yes, you have the names right. I appreciate your thoroughness in
making
sure
everything is OK. Every time you have reservations, there's usually
something
amiss. I just want to say, before I post the table structure, that
some
facts
concerning our situation may have been forgotten since our original
discussions. Please allow me to refresh our memories about
employees,
classifications and titles.
1. Our school employs both site staff (permanent) and substitutes
(temporary).

2. Each employee can only have 1 classification (Admin.,
Certificated
(teacher et. al), Classified and Substitutes). There are many
employees
who
have the same classification. tblClassifications 1:M tblEmployees,
correct?
For our purposes Admin. are strictly Admin.

3. Each employee can have one or many titles. Each title can be
assigned
to
many employees. tblTitles M:M tblTitlesEmps

The structure is as follows:

tblEmployees
Inactive Yes/No
EmpID PK Autonumber, long integer
ClassDescription FK to tblClassifications (number, long integer)
(This is what it *should* be. It's kind of messed up right now
because
of
tblEmpsClass which should be deleted.)
TitleDescription
(gasp!Illumination... I see what you're saying. This shouldn't be
here.)
LN
FN
MI

Let's go back to TitleDescription. We made that a subform within
tblEmployees. Do we keep it (now that I finally have it where I
want
it)
or
do we need to do something else?


tblSiteEmps 1:1 tblEmployees
EmpID (PK/FK)
Home Phone-txt
Cell Phone-txt
Address-txt
City-txt
State-txt
ZipCode-txt
EmerContactLN -txt
EmerContactFN- txt
EmerContactPhone - txt
PlaceofEmployment - txt
FamilyDr - txt
MedInsurance - txt
HospitalPref - txt
HealthIssues - txt
Medications- txt
Allergies - txt
DateCreated Date/Time
DateModified Date/Time

tblTitles
TitleID PK
TitleDescription

tblTitlesEmps
EmpID PK
TitleID number, l.i.(FK to tblTitles)


tblClassifications
ClassID PK
ClassDescriptions - txt (FK to tblClassifications)



Hopefully, the rest of it is OK. Good looking out...thank you so
much!
--
Aria W.


"Beetle" wrote:

I accidentally hit post before I was done with my last response.
Here
is the
complete response.

Just ignore my last post...
So this line should be Set rs = Me.tblEmployeesClone?

No. It should be Set rs = Me.RecordsetClone

What you're doing here is telling Access to create a copy of
whatever
the recordset is. You don't need to tell it the table or query
name.

Ok, I looked in tblEmployees. I didn't see anything. I do want
both
first


  #92  
Old July 16th, 2008, 04:39 AM posted to microsoft.public.access.gettingstarted
Aria
external usenet poster
 
Posts: 150
Default Still Struggling...

I don't have much time to reply today, but I have noted a few things inline.

Please, don't give it a second thought. I appreciate all of the support you
have both given me. I understand.

If you select the combo box, open the Property Sheet (with the tabs for
Format, Data, etc.), select an event, click the three dots, click Code
Builder, and click OK the name of the control will be filled in for you in
the code window. If you type it yourself you need the underscore. I think
that is so there are no spaces in the procedure name.


I'll check on that.

There's no definitive answer for that, but anything that involves junction
tables is a lot to get your mind around if you are just starting. Before
long, if it hasn't already happened, the need for junction tables, and how
to use them, will be clear in your mind. In your case there were a number
of junction tables, and a situation that involved keys, locks, people to
whom the keys were issued, locations of the locks, campuses, and a number of
other entities, with a variety of relationships between the entities.


Yeah, no kidding. I started thinking about that because I was trying to
avoid adding yet another junction table. I recall a previous discussion where
we decided that the room phone could go into tblLocations. That would leave
district cell phone orphaned and I could not figure out where to put it. It
doesn't belong in tblLocations and doesn't belong in tblEmployees so I
figured why am I drawing the line at this junction table when there are 5
others just like it. Oh well...c'est la vie! I keep looking at the
relationship diagram and I 'm concerned how I will manage all of this. In
particular, what kind of form to design and whether I should have another
subform for tbKleysRequests on frmEmployees. I'm trying not to borrow
trouble; one thing at a time.

What became of tblLocks? If one lock may have several keys, locks are the
top level.


"A lock can have several keys". There have been a number of turning points
in this journey. You both have dropped statements that on the surface seemed
inconsequential ,but in reality had a major impact. That is one thing I am
*never* going to forget. You made 3 on the mark statements in that post.
tblLocks is still here. It*is* a junction table, correct? It sure looks like
one.
Suggestions still on the table:
1. Create tblLocations to replace tblRooms.
2. Create tblLocks to define the relationsip between keys and locks. There
should be a 2 field PK involving Key ID and LocationID.
3. Create Master Key table to account for the special attributes of Master
Keys.
4. Create additional look-up tables: tblCampuses, tblWings and
tblLocationTypes.


Questions/Comments:
1.Decision--Unbeknowst to you and Beetle, I was going to use a natural key
for KeyID in tblKeys. Your statement about a possible re-key and our
history
of such finally made me realize that this was a *lousy* idea from the
beginning. I'm switching to autonumber.


There's nothing wrong with a natural key, depending on what it is. With a
surrogate key such as autonumber the main thing is that the record needs to
be unique for reasons apart from the autonumber field. If two records are
identical except for an artificial identifier then they are not really
unique. The autonumber is a convenience, but cannot by itself enforce what
is known as a unique constraint.


Won't this cause a problem? With the re-key, they not only changed the lock,
they changed the lock identifier. So if the key was previously, let's say,
SA-2 , it may have been changed to XJ-3A after the re-key. If I used this as
my primary key, I would have thought this would be a nightmarish situation.
No? If it happened once, there's always the possibility that it *could*
happen again. Keys are lost pretty much on a weekly basis. What do you thinK?
Do I need an inactive button for keys? I don't know exactly *how* this would
work.

Let me know what you think about that and the master keys. Don't concern
yourself if you don't have time. I have problems in the db that I need to
straighten out. Thanks so much for your time Bruce.

--
Aria W.


"BruceM" wrote:

I don't have much time to reply today, but I have noted a few things inline.

"Aria" wrote in message
...
I found the compile button. It was under commands so I added it to the
toolbar. Thanks.

I will take a look at your questions, but you will need to sort of start
over with your descriptions, as I have not been following very closely of
late. When you do so, list only the essential fields.


Not quite ready to list the table structures for this part yet...still
stinging from the last time when they were all wrong. I just basically
want
to think on post. Ask a few questions and have you weigh in on where I'm
going wrong. Are you Ok with that? I completely understand what you mean
as
far as having lost track. I have all my notes and posts and I still have
to
read up on what's going on and what transpired.

Questions unrelated to 2nd half of db:
1. When I input the programmng code for the AfterUpdate event, I input
cboStaff_Lookup. The line highlighted in yellow said, "Private Sub
cboStaff_Lookup_ AfterUpdate () Was I supposed to input that final
underscore
after Lookup?


If you select the combo box, open the Property Sheet (with the tabs for
Format, Data, etc.), select an event, click the three dots, click Code
Builder, and click OK the name of the control will be filled in for you in
the code window. If you type it yourself you need the underscore. I think
that is so there are no spaces in the procedure name.

2.Ever since this started taking off in earnest, I have often thought that
this db seems to be complicated; maybe that's just beginner's woe. I
don't
know because I don't have a point of reference. Both you and Beetle stated
in
your posts to each other in the beginning that it wasn't simple for a
first
app. My question is how did you know? We hadn't even really gotten into it
past the original 6 tables. How does one determine complexity?


There's no definitive answer for that, but anything that involves junction
tables is a lot to get your mind around if you are just starting. Before
long, if it hasn't already happened, the need for junction tables, and how
to use them, will be clear in your mind. In your case there were a number
of junction tables, and a situation that involved keys, locks, people to
whom the keys were issued, locations of the locks, campuses, and a number of
other entities, with a variety of relationships between the entities.

Hoping this is not too much for you in one post...

We know:
1. This is a staff database for a school setting.
2. We encompass 2 campuses.
3.Db emphasis is on keys because they have been problematic.
4. We have already suffered through a re-key of an entire campus,
including
the stadium, gyms and gates.
5. Many locations w/o a room #. (Ex. Auditorium, Stadium, Storage Rms.,
etc.)
6. Master keys allow general access for a single campus.
7. Master keys are unique, employee specific and their allocation is
severely restricted.
8. Storage, Stadium, Food Service and Gate Masters are location specific
*and* follow rule #7.
9. Wing masters will only open all rooms for a specific section of the
site.
10. Key assignments are based on job title, room assignment and
extracurricular duties.

Where we left off:
1. We had 4 tables relating to keys or location: tblRooms,
tblKeysEmployees
(junction), tblKeys and tblKeysRequests.


What became of tblLocks? If one lock may have several keys, locks are the
top level.

2. There was a lot of discussion involving home, personal cell, district
cell and room phone #s. The last decision was that home/personal cell is
part
of tblEmployees; district cell and room phone #s are part of tblphones.

Suggestions still on the table:
1. Create tblLocations to replace tblRooms.
2. Create tblLocks to define the relationsip between keys and locks. There
should be a 2 field PK involving Key ID and LocationID.
3. Create Master Key table to account for the special attributes of Master
Keys.
4. Create additional look-up tables: tblCampuses, tblWings and
tblLocationTypes.

If your eyes haven't glazed over... You don't have to answer today; I know
it's a lot.

Questions/Comments:
1.Decision--Unbeknowst to you and Beetle, I was going to use a natural key
for KeyID in tblKeys. Your statement about a possible re-key and our
history
of such finally made me realize that this was a *lousy* idea from the
beginning. I'm switching to autonumber.


There's nothing wrong with a natural key, depending on what it is. With a
surrogate key such as autonumber the main thing is that the record needs to
be unique for reasons apart from the autonumber field. If two records are
identical except for an artificial identifier then they are not really
unique. The autonumber is a convenience, but cannot by itself enforce what
is known as a unique constraint.


2. Master keys--This is a sub-type of key, correct? You can have one key
and
many masters or is it many sub-types (Gate, Stadium, etc.) But you can
also
have one specific master that has many keys assigned. While the master is
employee specific, it *is* essentially the same key that is assigned to
every
employee who has clearnace. It's just coded so we know in advance who we
gave
it to. This is a 1:M relationship? You can't have a M:M relationship with
sub-types can you? Either way it will have its own PK. This is where I'm
confusing myself and going around in circles.


I'll have to ponder this one later.


I'll stop here for now. Thanks!

--
Aria W.


"BruceM" wrote:

I think that Macros may be considered to be something other than code,
but
I'm not sure. If you use the wizard the code is added automatically.
You
can view it, but you may not know it was added. In any case, unless you
use
macros, which are rather limited, you pretty much need VBA code for
anything
other than a very simple database.
To find the Customize option I mentioned, open your database. In the
database window, click the Forms tab. Click View Code, or click the
Code
icon on the toolbar. What you see is the VBA editor. Right click a
blank
spot on the toolbar or menu bar. You should see Customize, probably as
the
last item on the list. There are of course other ways to open the VBA
editor, so choose another method if you prefer. The way you open it is
not
important (although I wouldn't try to customize while debugging).

I will take a look at your questions, but you will need to sort of start
over with your descriptions, as I have not been following very closely of
late. When you do so, list only the essential fields. For instance, for
tblEmployees:

EmployeeID (PK - Number)
LastName
FirstName
etc.

may be enough. For tblSiteEmps, list the PK/FK field, the relationship
type, and a few fields that will give the idea of how the table is used:

tblSiteEmps (1:1 tblEmployees)
EmpID (PK/FK)
Home Phone-txt
Address-txt
etc.

This is enough for our purposes. Give yourself a break from typing all
of
the details, unless for instance the fact there is a cell phone number is
relevant to the problem at hand, and make it easier for me or another
responder to read. Limit your description to a few typical fields, or to
fields that are part of your code or that are involved in relationships.


"Aria" wrote in message
...
You know I had never been to this section of my database before.
Originally,
I had no intention of putting in any programming code. I tried doing as
you
suggested but when I go to Customize...Options...I don't see what you
are
describing. What I see in the Options tab is Personalized Toolbar and
Menu
but it's greyed. The only button you can push is Reset my Usage Data
(?).
Maybe I'm in the wrong place.

I wanted to return to the 2nd half of the db. I still need to work on
tables
but I have questions (naturally!) Do you mind?
--
Aria W.


"BruceM" wrote:

I should have said 'Still in the VBA editor, click Debug Compile."
This
is in the menu bar, not in the Tools Options dialog. I like to
have
that
command readily available, so I added it to the toolbar. To do that,
right
click on the toolbar, click Customize, click the Options tab, click
Debug
on
the left, and drag Compile from the right side to the toolbar.

BTW, you could sort the row source for the Employee combo box by the
concatenated (LastFirst) field. If you sort on LastName you should
sort
on
FirstName next, in case two people have the same last name. You don't
need
to show the LastName and FirstName fields.

"Aria" wrote in message
...
Guess what? It works...it works! I'm trying real hard to hold it
together,
but I am so happy. sniff Thank you *so* much! OK, so let me tell
you
what
happened. I'm going to combine parts of both your posts.

Bruce M wrote:
If you view the SQL in datasheet view you will see that the first
column
is
EmpID. Column 1 should be the bound (hidden) column in
cboStaffLookup.
This statement:
rs.FindFirst "[EmpID] = " & Me.cboStaffLookup
means "Find the first record in the RecordsetClone in which EmpID is
the
same as EmpID in the combo box."

Beetle wrote:
A combo box will only display the first visible column in its
unexpanded
state, so in that case you would need to concantenate the names in
your
query as Bruce suggested. His example query might look like this in
design view;

Field: EmpID
Table:tblEmployees
Show: Yes (The box is checked).

Field:LastFirst:[LastName] & ", " & [FirstName]
Table:
Sort:
Show: Yes

Field: LastName
Table:tblEmployees
Sort: Ascending
Show: No

Aria writes:
It was the combination of both your posts that allowed me to follow
along
closely. You explained what was happening and then said this is what
it
will
look like.

Bruce M wrote:
Private Sub cboStaffLookup_AfterUpdate()

End Sub

The cursor should be blinking between those lines. Add the code.
After
you
enter:
Dim rs As Object
press the Enter key to go to a new line (or press it twice to create
some
space and make the code easier to read). Add:
Set rs = Me.RecordsetClone
Press the Enter key again, and add the next lines of code, pressing
the
Enter key after each one.

Scroll to the top of the code window and be sure the words Option
Explicit
are under Option Compare Database. Add them if they are not. If they

  #93  
Old July 16th, 2008, 02:38 PM posted to microsoft.public.access.gettingstarted
Aria
external usenet poster
 
Posts: 150
Default Still Struggling...

I think I may have a problem that I need to work through. We can discuss this
when you have time. I just wanted to get this down before I lose track and
start dealing with other issues. I think we are going to need to re-visit an
issue from the very first post: vault keys. Originally, we decided that the
situation was unclear and dropped it. In looking through some of the data
that I copied to help map my direction, I just noticed something that I
probably saw before but did not grab my attention as it has now. During the
re-key, among the many replacement keys made, one key was important enough to
be "assigned" to the vault. There are probably others, but that happened
before my time so I am not aware of the previous history. This does change
things a bit. I'm going to have to account for not only that key, but all of
the vault keys.

I have two trains of thought right now:

The first is that the vault key is a sub type key that will need its own
table. I don't know about this because it doesn't seem to fit the model of a
sub type (at least not as far as I can see). It's not like the masters which
are actually a different type of key. Their attributes are significantly
different. Not so with the vault key; there's nothing special or different
about them.

The second thought is that this is really a location type and will need to
be included with tbllocations or is it tbllocationtypes. I'm still working on
this because I'm unsure right now. It does seem to fit the "where" model
though.

Just throwing it out there...

--
Aria W.


"Aria" wrote:

I don't have much time to reply today, but I have noted a few things inline.


Please, don't give it a second thought. I appreciate all of the support you
have both given me. I understand.

If you select the combo box, open the Property Sheet (with the tabs for
Format, Data, etc.), select an event, click the three dots, click Code
Builder, and click OK the name of the control will be filled in for you in
the code window. If you type it yourself you need the underscore. I think
that is so there are no spaces in the procedure name.


I'll check on that.

There's no definitive answer for that, but anything that involves junction
tables is a lot to get your mind around if you are just starting. Before
long, if it hasn't already happened, the need for junction tables, and how
to use them, will be clear in your mind. In your case there were a number
of junction tables, and a situation that involved keys, locks, people to
whom the keys were issued, locations of the locks, campuses, and a number of
other entities, with a variety of relationships between the entities.


Yeah, no kidding. I started thinking about that because I was trying to
avoid adding yet another junction table. I recall a previous discussion where
we decided that the room phone could go into tblLocations. That would leave
district cell phone orphaned and I could not figure out where to put it. It
doesn't belong in tblLocations and doesn't belong in tblEmployees so I
figured why am I drawing the line at this junction table when there are 5
others just like it. Oh well...c'est la vie! I keep looking at the
relationship diagram and I 'm concerned how I will manage all of this. In
particular, what kind of form to design and whether I should have another
subform for tbKleysRequests on frmEmployees. I'm trying not to borrow
trouble; one thing at a time.

What became of tblLocks? If one lock may have several keys, locks are the
top level.


"A lock can have several keys". There have been a number of turning points
in this journey. You both have dropped statements that on the surface seemed
inconsequential ,but in reality had a major impact. That is one thing I am
*never* going to forget. You made 3 on the mark statements in that post.
tblLocks is still here. It*is* a junction table, correct? It sure looks like
one.
Suggestions still on the table:
1. Create tblLocations to replace tblRooms.
2. Create tblLocks to define the relationsip between keys and locks. There
should be a 2 field PK involving Key ID and LocationID.
3. Create Master Key table to account for the special attributes of Master
Keys.
4. Create additional look-up tables: tblCampuses, tblWings and
tblLocationTypes.


Questions/Comments:
1.Decision--Unbeknowst to you and Beetle, I was going to use a natural key
for KeyID in tblKeys. Your statement about a possible re-key and our
history
of such finally made me realize that this was a *lousy* idea from the
beginning. I'm switching to autonumber.


There's nothing wrong with a natural key, depending on what it is. With a
surrogate key such as autonumber the main thing is that the record needs to
be unique for reasons apart from the autonumber field. If two records are
identical except for an artificial identifier then they are not really
unique. The autonumber is a convenience, but cannot by itself enforce what
is known as a unique constraint.


Won't this cause a problem? With the re-key, they not only changed the lock,
they changed the lock identifier. So if the key was previously, let's say,
SA-2 , it may have been changed to XJ-3A after the re-key. If I used this as
my primary key, I would have thought this would be a nightmarish situation.
No? If it happened once, there's always the possibility that it *could*
happen again. Keys are lost pretty much on a weekly basis. What do you thinK?
Do I need an inactive button for keys? I don't know exactly *how* this would
work.

Let me know what you think about that and the master keys. Don't concern
yourself if you don't have time. I have problems in the db that I need to
straighten out. Thanks so much for your time Bruce.

--
Aria W.


"BruceM" wrote:

I don't have much time to reply today, but I have noted a few things inline.

"Aria" wrote in message
...
I found the compile button. It was under commands so I added it to the
toolbar. Thanks.

I will take a look at your questions, but you will need to sort of start
over with your descriptions, as I have not been following very closely of
late. When you do so, list only the essential fields.

Not quite ready to list the table structures for this part yet...still
stinging from the last time when they were all wrong. I just basically
want
to think on post. Ask a few questions and have you weigh in on where I'm
going wrong. Are you Ok with that? I completely understand what you mean
as
far as having lost track. I have all my notes and posts and I still have
to
read up on what's going on and what transpired.

Questions unrelated to 2nd half of db:
1. When I input the programmng code for the AfterUpdate event, I input
cboStaff_Lookup. The line highlighted in yellow said, "Private Sub
cboStaff_Lookup_ AfterUpdate () Was I supposed to input that final
underscore
after Lookup?


If you select the combo box, open the Property Sheet (with the tabs for
Format, Data, etc.), select an event, click the three dots, click Code
Builder, and click OK the name of the control will be filled in for you in
the code window. If you type it yourself you need the underscore. I think
that is so there are no spaces in the procedure name.

2.Ever since this started taking off in earnest, I have often thought that
this db seems to be complicated; maybe that's just beginner's woe. I
don't
know because I don't have a point of reference. Both you and Beetle stated
in
your posts to each other in the beginning that it wasn't simple for a
first
app. My question is how did you know? We hadn't even really gotten into it
past the original 6 tables. How does one determine complexity?


There's no definitive answer for that, but anything that involves junction
tables is a lot to get your mind around if you are just starting. Before
long, if it hasn't already happened, the need for junction tables, and how
to use them, will be clear in your mind. In your case there were a number
of junction tables, and a situation that involved keys, locks, people to
whom the keys were issued, locations of the locks, campuses, and a number of
other entities, with a variety of relationships between the entities.

Hoping this is not too much for you in one post...

We know:
1. This is a staff database for a school setting.
2. We encompass 2 campuses.
3.Db emphasis is on keys because they have been problematic.
4. We have already suffered through a re-key of an entire campus,
including
the stadium, gyms and gates.
5. Many locations w/o a room #. (Ex. Auditorium, Stadium, Storage Rms.,
etc.)
6. Master keys allow general access for a single campus.
7. Master keys are unique, employee specific and their allocation is
severely restricted.
8. Storage, Stadium, Food Service and Gate Masters are location specific
*and* follow rule #7.
9. Wing masters will only open all rooms for a specific section of the
site.
10. Key assignments are based on job title, room assignment and
extracurricular duties.

Where we left off:
1. We had 4 tables relating to keys or location: tblRooms,
tblKeysEmployees
(junction), tblKeys and tblKeysRequests.


What became of tblLocks? If one lock may have several keys, locks are the
top level.

2. There was a lot of discussion involving home, personal cell, district
cell and room phone #s. The last decision was that home/personal cell is
part
of tblEmployees; district cell and room phone #s are part of tblphones.

Suggestions still on the table:
1. Create tblLocations to replace tblRooms.
2. Create tblLocks to define the relationsip between keys and locks. There
should be a 2 field PK involving Key ID and LocationID.
3. Create Master Key table to account for the special attributes of Master
Keys.
4. Create additional look-up tables: tblCampuses, tblWings and
tblLocationTypes.

If your eyes haven't glazed over... You don't have to answer today; I know
it's a lot.

Questions/Comments:
1.Decision--Unbeknowst to you and Beetle, I was going to use a natural key
for KeyID in tblKeys. Your statement about a possible re-key and our
history
of such finally made me realize that this was a *lousy* idea from the
beginning. I'm switching to autonumber.


There's nothing wrong with a natural key, depending on what it is. With a
surrogate key such as autonumber the main thing is that the record needs to
be unique for reasons apart from the autonumber field. If two records are
identical except for an artificial identifier then they are not really
unique. The autonumber is a convenience, but cannot by itself enforce what
is known as a unique constraint.


2. Master keys--This is a sub-type of key, correct? You can have one key
and
many masters or is it many sub-types (Gate, Stadium, etc.) But you can
also
have one specific master that has many keys assigned. While the master is
employee specific, it *is* essentially the same key that is assigned to
every
employee who has clearnace. It's just coded so we know in advance who we
gave
it to. This is a 1:M relationship? You can't have a M:M relationship with
sub-types can you? Either way it will have its own PK. This is where I'm
confusing myself and going around in circles.


I'll have to ponder this one later.


I'll stop here for now. Thanks!

--
Aria W.


"BruceM" wrote:

I think that Macros may be considered to be something other than code,
but
I'm not sure. If you use the wizard the code is added automatically.
You
can view it, but you may not know it was added. In any case, unless you
use
macros, which are rather limited, you pretty much need VBA code for
anything
other than a very simple database.
To find the Customize option I mentioned, open your database. In the
database window, click the Forms tab. Click View Code, or click the
Code
icon on the toolbar. What you see is the VBA editor. Right click a
blank
spot on the toolbar or menu bar. You should see Customize, probably as
the
last item on the list. There are of course other ways to open the VBA
editor, so choose another method if you prefer. The way you open it is
not
important (although I wouldn't try to customize while debugging).

I will take a look at your questions, but you will need to sort of start
over with your descriptions, as I have not been following very closely of
late. When you do so, list only the essential fields. For instance, for
tblEmployees:

EmployeeID (PK - Number)
LastName
FirstName
etc.

may be enough. For tblSiteEmps, list the PK/FK field, the relationship
type, and a few fields that will give the idea of how the table is used:

tblSiteEmps (1:1 tblEmployees)
EmpID (PK/FK)
Home Phone-txt
Address-txt
etc.

This is enough for our purposes. Give yourself a break from typing all
of
the details, unless for instance the fact there is a cell phone number is
relevant to the problem at hand, and make it easier for me or another
responder to read. Limit your description to a few typical fields, or to
fields that are part of your code or that are involved in relationships.


"Aria" wrote in message
...
You know I had never been to this section of my database before.
Originally,
I had no intention of putting in any programming code. I tried doing as
you
suggested but when I go to Customize...Options...I don't see what you
are
describing. What I see in the Options tab is Personalized Toolbar and
Menu
but it's greyed. The only button you can push is Reset my Usage Data
(?).
Maybe I'm in the wrong place.

I wanted to return to the 2nd half of the db. I still need to work on
tables
but I have questions (naturally!) Do you mind?
--
Aria W.


"BruceM" wrote:

I should have said 'Still in the VBA editor, click Debug Compile."
This
is in the menu bar, not in the Tools Options dialog. I like to
have
that
command readily available, so I added it to the toolbar. To do that,
right
click on the toolbar, click Customize, click the Options tab, click

  #94  
Old July 17th, 2008, 12:53 PM posted to microsoft.public.access.gettingstarted
BruceM[_2_]
external usenet poster
 
Posts: 1,763
Default Still Struggling...

Is the vault key just like any other key for a particular lock, except that
it is in the vault? If so, is the vault copy essentially a clean copy to be
used as the master for additional copies? If so, you can identify the valut
key either by an extra field (maybe a Yes/No Vault field) in tblKeys, or you
can "assign" the key to the vault just as you would assign it to a person.
To do this you could add (Vault) to the top of the drop-down list of
Employees to whom keys are issued, similar to the way some drop-down lists
show (All) at the top. I won't go too far down that road until I hear back
from you.

Regarding the Locks table, I don't think it would be a junction table. A
lock is an entity with certain characteristics such as brand, location, date
installed, and so forth. One Lock can have many keys. Iff Master Keys are
included in the thinking, one Key can be for many Locks, but in this case
the junction table would be tblKeyLock or something like that.

Regarding tblKey, I expect there should be a Lost field or something like
that. There is no need to keep an active listing of keys nobody can find.
Regarding the question of natural key or surrogate key (any "artificial
identifier", including autonumber), it really doesn't matter as long as the
"natural" number such as SA-2 is used once for one physical (metal) key, and
never used again. If you are not sure this is the case, autonumber would be
a simpler choice as the PK. The same idea comes into play with the Lock
identifier, I expect. If they change the lock in such a way that the old
keys can be used you will need to update the FK of those keys so that they
are associated with the new lock.

From an earlier post you wrote:

Suggestions still on the table:
1. Create tblLocations to replace tblRooms

Sounds like a good idea
..
2. Create tblLocks to define the relationsip between keys and locks. There
should be a 2 field PK involving Key ID and LocationID.

Already discussed. Let me know if something is unclear, or if I am missing
something

3. Create Master Key table to account for the special attributes of Master
Keys.

One possibility is to see the situation as One Lock Many Keys and One Key
Many Locks, in which tblKeyLock is needed to resolve the relationship for

all locks and all keys. However, I think a separate table for MasterKeys
and a junction table tblKeyLock would be simpler to manage. If you are
looking at a Lock record you would have a subform listing the ordinary keys
and the person to whom they are assigned (some may not be assigned at all, I
expect). One Lock Many Keys, so there is a 1:M between tblLock and
tblKey, and the subform is based on tblKey. Another subform based on
tblKeyLock could list the master key holders.
One lock could have keys assigned to many people, and each person could be
assigned keys. Another consideration is that a Lock record should have a
listing of available keys. If it was me I think I would have an AssignedTo
field in tblKeys:

tblKeys
KeyID (PK)
LockID (FK to tblLocks)
KeyCode (S2-A, etc., or whatever)
AssignedTo (FK to tblEmployees)
AssignedDate
Retired (Yes/No)

If I wanted to list people and the keys they hold I would use a query.

This is not necessarily the best design in that AssignedTo and AssignedDate
are not really attributes of keys. The complexity here is that one person
may be assigned many keys, but a key can be assigned to only one person.
Similarly, one lock may have many keys, but other than master keys a key may
open only one lock. On the other hand, one person may open many locks, and
a lock may be opened by many people. By the way, it just occurred to me
that if there may be several locks keyed to accept the same key you may need
to add a LockLocation table related to tblLocks to take care of this detail.
One solution here may be to have a LockPerson junction table (one person
many locks and vice versa). This would be the source for a subform on the
Locks form. A list box could contain a listing of unassigned keys for that
lock. The list box row source would have to be built as you go, since the
available keys are always changing. When somebody needs to be assigned a
key you would go to the Lock form, see the listing of available keys, and
created a new LockPerson record that stores the KeyID, EmployeeID, and maybe
AssignedDate and other details.
It may be worth your while to start a new thread on this specific topic. All
you would need to say is that you have:
A Locks table containing the LockId, LockLocation, etc.
A Keys table containing KeyID (PK), LockID (FK), KeyCode, etc.
An Employee table

Explain that you understand a Lock may have many keys, and that a person may
be assigned many keys. However, you are unsure how to store the AssignedTo
information for Keys. Should it be in the Keys table? If not, how is that
relationship modeled.

I suggest this because frankly I am unsure how best to proceed on this
point, and in a new thread you would attract the attention of very
experienced designers.

4. Create additional look-up tables: tblCampuses, tblWings and
tblLocationTypes.

Sounds good.

**********

"Aria" wrote in message
...
I think I may have a problem that I need to work through. We can discuss
this
when you have time. I just wanted to get this down before I lose track and
start dealing with other issues. I think we are going to need to re-visit
an
issue from the very first post: vault keys. Originally, we decided that
the
situation was unclear and dropped it. In looking through some of the data
that I copied to help map my direction, I just noticed something that I
probably saw before but did not grab my attention as it has now. During
the
re-key, among the many replacement keys made, one key was important enough
to
be "assigned" to the vault. There are probably others, but that happened
before my time so I am not aware of the previous history. This does change
things a bit. I'm going to have to account for not only that key, but all
of
the vault keys.

I have two trains of thought right now:

The first is that the vault key is a sub type key that will need its own
table. I don't know about this because it doesn't seem to fit the model of
a
sub type (at least not as far as I can see). It's not like the masters
which
are actually a different type of key. Their attributes are significantly
different. Not so with the vault key; there's nothing special or different
about them.

The second thought is that this is really a location type and will need to
be included with tbllocations or is it tbllocationtypes. I'm still working
on
this because I'm unsure right now. It does seem to fit the "where" model
though.

Just throwing it out there...

--
Aria W.


"Aria" wrote:

I don't have much time to reply today, but I have noted a few things
inline.


Please, don't give it a second thought. I appreciate all of the support
you
have both given me. I understand.

If you select the combo box, open the Property Sheet (with the tabs for
Format, Data, etc.), select an event, click the three dots, click Code
Builder, and click OK the name of the control will be filled in for you
in
the code window. If you type it yourself you need the underscore. I
think
that is so there are no spaces in the procedure name.


I'll check on that.

There's no definitive answer for that, but anything that involves
junction
tables is a lot to get your mind around if you are just starting.
Before
long, if it hasn't already happened, the need for junction tables, and
how
to use them, will be clear in your mind. In your case there were a
number
of junction tables, and a situation that involved keys, locks, people
to
whom the keys were issued, locations of the locks, campuses, and a
number of
other entities, with a variety of relationships between the entities.


Yeah, no kidding. I started thinking about that because I was trying to
avoid adding yet another junction table. I recall a previous discussion
where
we decided that the room phone could go into tblLocations. That would
leave
district cell phone orphaned and I could not figure out where to put it.
It
doesn't belong in tblLocations and doesn't belong in tblEmployees so I
figured why am I drawing the line at this junction table when there are 5
others just like it. Oh well...c'est la vie! I keep looking at the
relationship diagram and I 'm concerned how I will manage all of this. In
particular, what kind of form to design and whether I should have
another
subform for tbKleysRequests on frmEmployees. I'm trying not to borrow
trouble; one thing at a time.

What became of tblLocks? If one lock may have several keys, locks are

the
top level.


"A lock can have several keys". There have been a number of turning
points
in this journey. You both have dropped statements that on the surface
seemed
inconsequential ,but in reality had a major impact. That is one thing I
am
*never* going to forget. You made 3 on the mark statements in that post.
tblLocks is still here. It*is* a junction table, correct? It sure looks
like
one.
Suggestions still on the table:
1. Create tblLocations to replace tblRooms.
2. Create tblLocks to define the relationsip between keys and locks.
There
should be a 2 field PK involving Key ID and LocationID.
3. Create Master Key table to account for the special attributes of
Master
Keys.
4. Create additional look-up tables: tblCampuses, tblWings and
tblLocationTypes.


Questions/Comments:
1.Decision--Unbeknowst to you and Beetle, I was going to use a
natural key
for KeyID in tblKeys. Your statement about a possible re-key and our
history
of such finally made me realize that this was a *lousy* idea from the
beginning. I'm switching to autonumber.

There's nothing wrong with a natural key, depending on what it is.
With a
surrogate key such as autonumber the main thing is that the record
needs to
be unique for reasons apart from the autonumber field. If two records
are
identical except for an artificial identifier then they are not really
unique. The autonumber is a convenience, but cannot by itself enforce
what
is known as a unique constraint.


Won't this cause a problem? With the re-key, they not only changed the
lock,
they changed the lock identifier. So if the key was previously, let's
say,
SA-2 , it may have been changed to XJ-3A after the re-key. If I used this
as
my primary key, I would have thought this would be a nightmarish
situation.
No? If it happened once, there's always the possibility that it *could*
happen again. Keys are lost pretty much on a weekly basis. What do you
thinK?
Do I need an inactive button for keys? I don't know exactly *how* this
would
work.

Let me know what you think about that and the master keys. Don't concern
yourself if you don't have time. I have problems in the db that I need to
straighten out. Thanks so much for your time Bruce.

--
Aria W.


"BruceM" wrote:

I don't have much time to reply today, but I have noted a few things
inline.

"Aria" wrote in message
...
I found the compile button. It was under commands so I added it to the
toolbar. Thanks.

I will take a look at your questions, but you will need to sort of
start
over with your descriptions, as I have not been following very
closely of
late. When you do so, list only the essential fields.

Not quite ready to list the table structures for this part
yet...still
stinging from the last time when they were all wrong. I just
basically
want
to think on post. Ask a few questions and have you weigh in on where
I'm
going wrong. Are you Ok with that? I completely understand what you
mean
as
far as having lost track. I have all my notes and posts and I still
have
to
read up on what's going on and what transpired.

Questions unrelated to 2nd half of db:
1. When I input the programmng code for the AfterUpdate event, I
input
cboStaff_Lookup. The line highlighted in yellow said, "Private Sub
cboStaff_Lookup_ AfterUpdate () Was I supposed to input that final
underscore
after Lookup?

If you select the combo box, open the Property Sheet (with the tabs for
Format, Data, etc.), select an event, click the three dots, click Code
Builder, and click OK the name of the control will be filled in for you
in
the code window. If you type it yourself you need the underscore. I
think
that is so there are no spaces in the procedure name.

2.Ever since this started taking off in earnest, I have often thought
that
this db seems to be complicated; maybe that's just beginner's woe. I
don't
know because I don't have a point of reference. Both you and Beetle
stated
in
your posts to each other in the beginning that it wasn't simple for a
first
app. My question is how did you know? We hadn't even really gotten
into it
past the original 6 tables. How does one determine complexity?

There's no definitive answer for that, but anything that involves
junction
tables is a lot to get your mind around if you are just starting.
Before
long, if it hasn't already happened, the need for junction tables, and
how
to use them, will be clear in your mind. In your case there were a
number
of junction tables, and a situation that involved keys, locks, people
to
whom the keys were issued, locations of the locks, campuses, and a
number of
other entities, with a variety of relationships between the entities.

Hoping this is not too much for you in one post...

We know:
1. This is a staff database for a school setting.
2. We encompass 2 campuses.
3.Db emphasis is on keys because they have been problematic.
4. We have already suffered through a re-key of an entire campus,
including
the stadium, gyms and gates.
5. Many locations w/o a room #. (Ex. Auditorium, Stadium, Storage
Rms.,
etc.)
6. Master keys allow general access for a single campus.
7. Master keys are unique, employee specific and their allocation is
severely restricted.
8. Storage, Stadium, Food Service and Gate Masters are location
specific
*and* follow rule #7.
9. Wing masters will only open all rooms for a specific section of
the
site.
10. Key assignments are based on job title, room assignment and
extracurricular duties.

Where we left off:
1. We had 4 tables relating to keys or location: tblRooms,
tblKeysEmployees
(junction), tblKeys and tblKeysRequests.

What became of tblLocks? If one lock may have several keys, locks are
the
top level.

2. There was a lot of discussion involving home, personal cell,
district
cell and room phone #s. The last decision was that home/personal cell
is
part
of tblEmployees; district cell and room phone #s are part of
tblphones.

Suggestions still on the table:
1. Create tblLocations to replace tblRooms.
2. Create tblLocks to define the relationsip between keys and locks.
There
should be a 2 field PK involving Key ID and LocationID.
3. Create Master Key table to account for the special attributes of
Master
Keys.
4. Create additional look-up tables: tblCampuses, tblWings and
tblLocationTypes.

If your eyes haven't glazed over... You don't have to answer today; I
know
it's a lot.

Questions/Comments:
1.Decision--Unbeknowst to you and Beetle, I was going to use a
natural key
for KeyID in tblKeys. Your statement about a possible re-key and our
history
of such finally made me realize that this was a *lousy* idea from the
beginning. I'm switching to autonumber.

There's nothing wrong with a natural key, depending on what it is.
With a
surrogate key such as autonumber the main thing is that the record
needs to
be unique for reasons apart from the autonumber field. If two records
are
identical except for an artificial identifier then they are not really
unique. The autonumber is a convenience, but cannot by itself enforce
what
is known as a unique constraint.


2. Master keys--This is a sub-type of key, correct? You can have one
key
and
many masters or is it many sub-types (Gate, Stadium, etc.) But you
can
also
have one specific master that has many keys assigned. While the
master is
employee specific, it *is* essentially the same key that is assigned
to
every
employee who has clearnace. It's just coded so we know in advance who
we
gave
it to. This is a 1:M relationship? You can't have a M:M relationship
with
sub-types can you? Either way it will have its own PK. This is where
I'm
confusing myself and going around in circles.

I'll have to ponder this one later.


I'll stop here for now. Thanks!

--
Aria W.


"BruceM" wrote:

I think that Macros may be considered to be something other than
code,
but
I'm not sure. If you use the wizard the code is added
automatically.
You
can view it, but you may not know it was added. In any case, unless
you
use
macros, which are rather limited, you pretty much need VBA code for
anything
other than a very simple database.
To find the Customize option I mentioned, open your database. In
the
database window, click the Forms tab. Click View Code, or click
the
Code
icon on the toolbar. What you see is the VBA editor. Right click a
blank
spot on the toolbar or menu bar. You should see Customize, probably
as
the
last item on the list. There are of course other ways to open the
VBA
editor, so choose another method if you prefer. The way you open it
is
not
important (although I wouldn't try to customize while debugging).

I will take a look at your questions, but you will need to sort of
start
over with your descriptions, as I have not been following very
closely of
late. When you do so, list only the essential fields. For
instance, for
tblEmployees:

EmployeeID (PK - Number)
LastName
FirstName
etc.

may be enough. For tblSiteEmps, list the PK/FK field, the
relationship
type, and a few fields that will give the idea of how the table is
used:

tblSiteEmps (1:1 tblEmployees)
EmpID (PK/FK)
Home Phone-txt
Address-txt
etc.

This is enough for our purposes. Give yourself a break from typing
all
of
the details, unless for instance the fact there is a cell phone
number is
relevant to the problem at hand, and make it easier for me or
another
responder to read. Limit your description to a few typical fields,
or to
fields that are part of your code or that are involved in
relationships.


"Aria" wrote in message
...
You know I had never been to this section of my database before.
Originally,
I had no intention of putting in any programming code. I tried
doing as
you
suggested but when I go to Customize...Options...I don't see what
you
are
describing. What I see in the Options tab is Personalized Toolbar
and
Menu
but it's greyed. The only button you can push is Reset my Usage
Data
(?).
Maybe I'm in the wrong place.

I wanted to return to the 2nd half of the db. I still need to work
on
tables
but I have questions (naturally!) Do you mind?
--
Aria W.


"BruceM" wrote:

I should have said 'Still in the VBA editor, click Debug
Compile."
This
is in the menu bar, not in the Tools Options dialog. I like
to
have
that
command readily available, so I added it to the toolbar. To do
that,
right
click on the toolbar, click Customize, click the Options tab,
click


  #95  
Old July 17th, 2008, 07:20 PM posted to microsoft.public.access.gettingstarted
Aria
external usenet poster
 
Posts: 150
Default Still Struggling...

First, thank you for your honesty. I smiled reading your post. That is the
same thing that happens to me. I think, "hmmm...it could be like this...but
then what about that...oh, and I forgot to account for this...but then I have
to switch that...and the next thing you know, I'm right back where I started.
g I don't think you go through quite the same thing because you have a
*lot* more experience but it *is* confusing.
While keys are what drove my desire to create this db in the first place,
this is also the section I have been dreading. I reviewed all of our posts
and took notes on what was suggested and any decisions that were made. When I
refer to a statement as from a post in the beginning, that's what I mean. So,
let's see if we can make any progress on some of these areas.

Is the vault key just like any other key for a particular lock, except that it is in the vault?


Yes.

If so, is the vault copy essentially a clean copy to be used as the master for additional copies?


No, although at times they may come and borrow a key to make a quick copy if
they are already on campus and I just need one or two. It's rare. The
district has its own locksmith who are permanent staff. They have the
originals or blanks or whatever they call them.

If so, you can identify the valut key either by an extra field (maybe a Yes/No Vault field) in tblKeys, or you can "assign" the key to the vault just as you would assign it to a person.


Ok, what happened here? We have apparently switched our origianl positions.
I suggested assigning the vault key like an employee key in the very first
post, but after learning about table attributes from the two of you ( I will
never forget tblSubs), I no longer hold that position. You two are absolutely
right. It isn't an employee attribute.
I don't think it should be a yes/no field because of the sheer number of
keys we're talking about...approx. 400. Am I going to run into problems with
that many yes/no boxes? You may be right about this. I'm not sure because
again, I don't have the experience behind me. So where does that leave us?

Are you oppossed to the vault table or vault as a location in
tbllocations(now that I think about it, somethings wrong with this line of
thinking but I'm not sure what)?

Regarding the Locks table, I don't think it would be a junction table.


I 'm now confused about the purpose and fields in this table. You had posted
in the beginning that it should include lookup tables for campus, wing and
roomtype. I by no means expect you to remember this because I didn't either.
There was a lot of discussion about a great many things. I'm only mentioning
it now because you asked me to post my table structure for this part of the
db. I was unsure about some of the structure and wanted to make sure I had it
right before I posted. It was a confusing mess that I had to keep looking at.
I couldn't make heads nor tails of what it should be. I had to live with it
awhile. I had to sit down and go through all the posts suggestions and
advice, move fields from one place to another, change table names and add
fields and lookup tables. When I finished the only fields left in tblLocker
were KeyID and LocationID. I originally had campus and wing in this section
but once we changed tblRooms to tblLocations, it seemed better suited in
tblLocations. Since I was now left with only 2 fields in tblLocks, I started
wondering if it was a junction table.

There is no need to keep an active listing of keys nobody can find.


lol ...good one! No, let's not.

I'm going to post my table structure later today, even though it still needs
work. I know there are mistakes and that there is plenty of room for
improvement, but you have posted additional comments that I believe (if I'm
not mistaken) may have been addressed within the structure.

--
Aria W.


"BruceM" wrote:

Is the vault key just like any other key for a particular lock, except that
it is in the vault? If so, is the vault copy essentially a clean copy to be
used as the master for additional copies? If so, you can identify the valut
key either by an extra field (maybe a Yes/No Vault field) in tblKeys, or you
can "assign" the key to the vault just as you would assign it to a person.
To do this you could add (Vault) to the top of the drop-down list of
Employees to whom keys are issued, similar to the way some drop-down lists
show (All) at the top. I won't go too far down that road until I hear back
from you.

Regarding the Locks table, I don't think it would be a junction table. A
lock is an entity with certain characteristics such as brand, location, date
installed, and so forth. One Lock can have many keys. Iff Master Keys are
included in the thinking, one Key can be for many Locks, but in this case
the junction table would be tblKeyLock or something like that.

Regarding tblKey, I expect there should be a Lost field or something like
that. There is no need to keep an active listing of keys nobody can find.
Regarding the question of natural key or surrogate key (any "artificial
identifier", including autonumber), it really doesn't matter as long as the
"natural" number such as SA-2 is used once for one physical (metal) key, and
never used again. If you are not sure this is the case, autonumber would be
a simpler choice as the PK. The same idea comes into play with the Lock
identifier, I expect. If they change the lock in such a way that the old
keys can be used you will need to update the FK of those keys so that they
are associated with the new lock.

From an earlier post you wrote:

Suggestions still on the table:
1. Create tblLocations to replace tblRooms

Sounds like a good idea
..
2. Create tblLocks to define the relationsip between keys and locks. There
should be a 2 field PK involving Key ID and LocationID.

Already discussed. Let me know if something is unclear, or if I am missing
something

3. Create Master Key table to account for the special attributes of Master
Keys.

One possibility is to see the situation as One Lock Many Keys and One Key
Many Locks, in which tblKeyLock is needed to resolve the relationship for

all locks and all keys. However, I think a separate table for MasterKeys
and a junction table tblKeyLock would be simpler to manage. If you are
looking at a Lock record you would have a subform listing the ordinary keys
and the person to whom they are assigned (some may not be assigned at all, I
expect). One Lock Many Keys, so there is a 1:M between tblLock and
tblKey, and the subform is based on tblKey. Another subform based on
tblKeyLock could list the master key holders.
One lock could have keys assigned to many people, and each person could be
assigned keys. Another consideration is that a Lock record should have a
listing of available keys. If it was me I think I would have an AssignedTo
field in tblKeys:

tblKeys
KeyID (PK)
LockID (FK to tblLocks)
KeyCode (S2-A, etc., or whatever)
AssignedTo (FK to tblEmployees)
AssignedDate
Retired (Yes/No)

If I wanted to list people and the keys they hold I would use a query.

This is not necessarily the best design in that AssignedTo and AssignedDate
are not really attributes of keys. The complexity here is that one person
may be assigned many keys, but a key can be assigned to only one person.
Similarly, one lock may have many keys, but other than master keys a key may
open only one lock. On the other hand, one person may open many locks, and
a lock may be opened by many people. By the way, it just occurred to me
that if there may be several locks keyed to accept the same key you may need
to add a LockLocation table related to tblLocks to take care of this detail.
One solution here may be to have a LockPerson junction table (one person
many locks and vice versa). This would be the source for a subform on the
Locks form. A list box could contain a listing of unassigned keys for that
lock. The list box row source would have to be built as you go, since the
available keys are always changing. When somebody needs to be assigned a
key you would go to the Lock form, see the listing of available keys, and
created a new LockPerson record that stores the KeyID, EmployeeID, and maybe
AssignedDate and other details.
It may be worth your while to start a new thread on this specific topic. All
you would need to say is that you have:
A Locks table containing the LockId, LockLocation, etc.
A Keys table containing KeyID (PK), LockID (FK), KeyCode, etc.
An Employee table

Explain that you understand a Lock may have many keys, and that a person may
be assigned many keys. However, you are unsure how to store the AssignedTo
information for Keys. Should it be in the Keys table? If not, how is that
relationship modeled.

I suggest this because frankly I am unsure how best to proceed on this
point, and in a new thread you would attract the attention of very
experienced designers.

4. Create additional look-up tables: tblCampuses, tblWings and
tblLocationTypes.

Sounds good.

**********

"Aria" wrote in message
...
I think I may have a problem that I need to work through. We can discuss
this
when you have time. I just wanted to get this down before I lose track and
start dealing with other issues. I think we are going to need to re-visit
an
issue from the very first post: vault keys. Originally, we decided that
the
situation was unclear and dropped it. In looking through some of the data
that I copied to help map my direction, I just noticed something that I
probably saw before but did not grab my attention as it has now. During
the
re-key, among the many replacement keys made, one key was important enough
to
be "assigned" to the vault. There are probably others, but that happened
before my time so I am not aware of the previous history. This does change
things a bit. I'm going to have to account for not only that key, but all
of
the vault keys.

I have two trains of thought right now:

The first is that the vault key is a sub type key that will need its own
table. I don't know about this because it doesn't seem to fit the model of
a
sub type (at least not as far as I can see). It's not like the masters
which
are actually a different type of key. Their attributes are significantly
different. Not so with the vault key; there's nothing special or different
about them.

The second thought is that this is really a location type and will need to
be included with tbllocations or is it tbllocationtypes. I'm still working
on
this because I'm unsure right now. It does seem to fit the "where" model
though.

Just throwing it out there...

--
Aria W.


"Aria" wrote:

I don't have much time to reply today, but I have noted a few things
inline.

Please, don't give it a second thought. I appreciate all of the support
you
have both given me. I understand.

If you select the combo box, open the Property Sheet (with the tabs for
Format, Data, etc.), select an event, click the three dots, click Code
Builder, and click OK the name of the control will be filled in for you
in
the code window. If you type it yourself you need the underscore. I
think
that is so there are no spaces in the procedure name.

I'll check on that.

There's no definitive answer for that, but anything that involves
junction
tables is a lot to get your mind around if you are just starting.
Before
long, if it hasn't already happened, the need for junction tables, and
how
to use them, will be clear in your mind. In your case there were a
number
of junction tables, and a situation that involved keys, locks, people
to
whom the keys were issued, locations of the locks, campuses, and a
number of
other entities, with a variety of relationships between the entities.

Yeah, no kidding. I started thinking about that because I was trying to
avoid adding yet another junction table. I recall a previous discussion
where
we decided that the room phone could go into tblLocations. That would
leave
district cell phone orphaned and I could not figure out where to put it.
It
doesn't belong in tblLocations and doesn't belong in tblEmployees so I
figured why am I drawing the line at this junction table when there are 5
others just like it. Oh well...c'est la vie! I keep looking at the
relationship diagram and I 'm concerned how I will manage all of this. In
particular, what kind of form to design and whether I should have
another
subform for tbKleysRequests on frmEmployees. I'm trying not to borrow
trouble; one thing at a time.

What became of tblLocks? If one lock may have several keys, locks are
the
top level.

"A lock can have several keys". There have been a number of turning
points
in this journey. You both have dropped statements that on the surface
seemed
inconsequential ,but in reality had a major impact. That is one thing I
am
*never* going to forget. You made 3 on the mark statements in that post.
tblLocks is still here. It*is* a junction table, correct? It sure looks
like
one.
Suggestions still on the table:
1. Create tblLocations to replace tblRooms.
2. Create tblLocks to define the relationsip between keys and locks.
There
should be a 2 field PK involving Key ID and LocationID.
3. Create Master Key table to account for the special attributes of
Master
Keys.
4. Create additional look-up tables: tblCampuses, tblWings and
tblLocationTypes.

Questions/Comments:
1.Decision--Unbeknowst to you and Beetle, I was going to use a
natural key
for KeyID in tblKeys. Your statement about a possible re-key and our
history
of such finally made me realize that this was a *lousy* idea from the
beginning. I'm switching to autonumber.

There's nothing wrong with a natural key, depending on what it is.
With a
surrogate key such as autonumber the main thing is that the record
needs to
be unique for reasons apart from the autonumber field. If two records
are
identical except for an artificial identifier then they are not really
unique. The autonumber is a convenience, but cannot by itself enforce
what
is known as a unique constraint.

Won't this cause a problem? With the re-key, they not only changed the
lock,
they changed the lock identifier. So if the key was previously, let's
say,
SA-2 , it may have been changed to XJ-3A after the re-key. If I used this
as
my primary key, I would have thought this would be a nightmarish
situation.
No? If it happened once, there's always the possibility that it *could*
happen again. Keys are lost pretty much on a weekly basis. What do you
thinK?
Do I need an inactive button for keys? I don't know exactly *how* this
would
work.

Let me know what you think about that and the master keys. Don't concern
yourself if you don't have time. I have problems in the db that I need to
straighten out. Thanks so much for your time Bruce.

--
Aria W.


"BruceM" wrote:

I don't have much time to reply today, but I have noted a few things
inline.

"Aria" wrote in message
...
I found the compile button. It was under commands so I added it to the
toolbar. Thanks.

I will take a look at your questions, but you will need to sort of
start
over with your descriptions, as I have not been following very
closely of
late. When you do so, list only the essential fields.

Not quite ready to list the table structures for this part
yet...still
stinging from the last time when they were all wrong. I just
basically
want
to think on post. Ask a few questions and have you weigh in on where
I'm
going wrong. Are you Ok with that? I completely understand what you
mean
as
far as having lost track. I have all my notes and posts and I still
have
to
read up on what's going on and what transpired.

Questions unrelated to 2nd half of db:
1. When I input the programmng code for the AfterUpdate event, I
input
cboStaff_Lookup. The line highlighted in yellow said, "Private Sub
cboStaff_Lookup_ AfterUpdate () Was I supposed to input that final
underscore
after Lookup?

  #96  
Old July 17th, 2008, 08:11 PM posted to microsoft.public.access.gettingstarted
BruceM[_2_]
external usenet poster
 
Posts: 1,763
Default Still Struggling...


"Aria" wrote in message
...
First, thank you for your honesty. I smiled reading your post. That is the
same thing that happens to me. I think, "hmmm...it could be like
this...but
then what about that...oh, and I forgot to account for this...but then I
have
to switch that...and the next thing you know, I'm right back where I
started.
g I don't think you go through quite the same thing because you have a
*lot* more experience but it *is* confusing.
While keys are what drove my desire to create this db in the first place,
this is also the section I have been dreading. I reviewed all of our posts
and took notes on what was suggested and any decisions that were made.
When I
refer to a statement as from a post in the beginning, that's what I mean.
So,
let's see if we can make any progress on some of these areas.

Is the vault key just like any other key for a particular lock, except
that it is in the vault?


Yes.

If so, is the vault copy essentially a clean copy to be used as the master
for additional copies?


No, although at times they may come and borrow a key to make a quick copy
if
they are already on campus and I just need one or two. It's rare. The
district has its own locksmith who are permanent staff. They have the
originals or blanks or whatever they call them.

If so, you can identify the valut key either by an extra field (maybe a
Yes/No Vault field) in tblKeys, or you can "assign" the key to the vault
just as you would assign it to a person.


Ok, what happened here? We have apparently switched our origianl
positions.
I suggested assigning the vault key like an employee key in the very first
post, but after learning about table attributes from the two of you ( I
will
never forget tblSubs), I no longer hold that position. You two are
absolutely
right. It isn't an employee attribute.
I don't think it should be a yes/no field because of the sheer number of
keys we're talking about...approx. 400. Am I going to run into problems
with
that many yes/no boxes? You may be right about this. I'm not sure because
again, I don't have the experience behind me. So where does that leave us?

I don't know if it is a switch or not, but the fact is you are assigning the
key to the vault. Take a look at this:
http://www.mvps.org/access/forms/frm0043.htm

It explains how to produce a list such as this:

(Vault)
Adams, John
Adams, John Quincy
Jefferson, Thomas
Madison, James
Monroe, James
Washington, George

When you select (Vault) you can have the AssignedTo field be null or 0. In
a query you could have something like this:
AssignedEntity: IIf([AssignedTo] Is Null,"Vault",[LastName] & ", " &
[FirstName])

The code in the link I provided (use the part at the top of the page, not
the part that talks about a Value List) adds a sort of artificial record to
the Employees listing, but it *does not* create an employee record.

Are you oppossed to the vault table or vault as a location in
tbllocations(now that I think about it, somethings wrong with this line of
thinking but I'm not sure what)?


The vault is issued a key. We can modify the part about keys being assigned
to people to say that keys are assigned to entities including people. The
vault is in a location, but it is not a location. If the vault has a keyed
lock there is a corresponding record in tblLocks, including Location
information.

Regarding the Locks table, I don't think it would be a junction table.


I 'm now confused about the purpose and fields in this table. You had
posted
in the beginning that it should include lookup tables for campus, wing and
roomtype. I by no means expect you to remember this because I didn't
either.
There was a lot of discussion about a great many things. I'm only
mentioning
it now because you asked me to post my table structure for this part of
the
db. I was unsure about some of the structure and wanted to make sure I had
it
right before I posted. It was a confusing mess that I had to keep looking
at.
I couldn't make heads nor tails of what it should be. I had to live with
it
awhile. I had to sit down and go through all the posts suggestions and
advice, move fields from one place to another, change table names and add
fields and lookup tables. When I finished the only fields left in
tblLocker
were KeyID and LocationID. I originally had campus and wing in this
section
but once we changed tblRooms to tblLocations, it seemed better suited in
tblLocations. Since I was now left with only 2 fields in tblLocks, I
started
wondering if it was a junction table.


Let's say Room 222 of Building A on the South campus has a lock with Serial
Number 12345. Your tblLocks would be something like this:

tblLocks
LockID LNumber LCampus LBuilding LLocation
111 12345 South Building A Room 222

You can store numbers instead of text for LBuilding, etc. If somebody
changes the building name the keys will remain the same, and all records
will reflect the new name. For now just assume the text value is stored.

One Lock can have many keys. Therefore tblKeys is something like this:

tblKeys
KeyID (PK)
LockID (FK)
KeyNumber (SA-12 or whatever)
Retired (Yes/No)

The Key records for Lock 111 could be something like this:

KeyID LockID KeyNumber
1 111 SA-1
2 111 SA-2
3 111 SA-3

Note that each key record is associated with a Lock record. KeyID is not a
part of the lock record, but rather the other way around. The lock has
keys. The key does not have locks.

You will note I have used several location fields (Campus, Building, and
Location). If several buildings have a Room 222, or several campuses have a
Maintenance Shed, or something like that, then you will need all three
location types to identify where you are in at least some cases. After
selecting South Campus the Building combo box could be limited to just
buildings on the South Campus. Similarly, the Room combo box could limit
Room Numbers in the selected building. More on this later, if you like, but
you can ignore it for now.


There is no need to keep an active listing of keys nobody can find.


lol ...good one! No, let's not.


There are more such listings than you may imagine.

I'm going to post my table structure later today, even though it still
needs
work. I know there are mistakes and that there is plenty of room for
improvement, but you have posted additional comments that I believe (if
I'm
not mistaken) may have been addressed within the structure.


I will wait to see what you post, and will add some comments tomorrow,
including (if I can) a strategy for the junction table for storing
KeyAssignment information, but after that I will be away for a week. I
guess Sean will be back, so I hope I'm not at cross purposes with him to too
great an extent.

--
Aria W.


"BruceM" wrote:

Is the vault key just like any other key for a particular lock, except
that
it is in the vault? If so, is the vault copy essentially a clean copy to
be
used as the master for additional copies? If so, you can identify the
valut
key either by an extra field (maybe a Yes/No Vault field) in tblKeys, or
you
can "assign" the key to the vault just as you would assign it to a
person.
To do this you could add (Vault) to the top of the drop-down list of
Employees to whom keys are issued, similar to the way some drop-down
lists
show (All) at the top. I won't go too far down that road until I hear
back
from you.

Regarding the Locks table, I don't think it would be a junction table. A
lock is an entity with certain characteristics such as brand, location,
date
installed, and so forth. One Lock can have many keys. Iff Master Keys
are
included in the thinking, one Key can be for many Locks, but in this case
the junction table would be tblKeyLock or something like that.

Regarding tblKey, I expect there should be a Lost field or something like
that. There is no need to keep an active listing of keys nobody can
find.
Regarding the question of natural key or surrogate key (any "artificial
identifier", including autonumber), it really doesn't matter as long as
the
"natural" number such as SA-2 is used once for one physical (metal) key,
and
never used again. If you are not sure this is the case, autonumber would
be
a simpler choice as the PK. The same idea comes into play with the Lock
identifier, I expect. If they change the lock in such a way that the old
keys can be used you will need to update the FK of those keys so that
they
are associated with the new lock.

From an earlier post you wrote:

Suggestions still on the table:
1. Create tblLocations to replace tblRooms

Sounds like a good idea
..
2. Create tblLocks to define the relationsip between keys and locks.
There
should be a 2 field PK involving Key ID and LocationID.

Already discussed. Let me know if something is unclear, or if I am
missing
something

3. Create Master Key table to account for the special attributes of
Master
Keys.

One possibility is to see the situation as One Lock Many Keys and One
Key
Many Locks, in which tblKeyLock is needed to resolve the relationship

for
all locks and all keys. However, I think a separate table for MasterKeys
and a junction table tblKeyLock would be simpler to manage. If you are
looking at a Lock record you would have a subform listing the ordinary
keys
and the person to whom they are assigned (some may not be assigned at
all, I
expect). One Lock Many Keys, so there is a 1:M between tblLock and
tblKey, and the subform is based on tblKey. Another subform based on
tblKeyLock could list the master key holders.
One lock could have keys assigned to many people, and each person could
be
assigned keys. Another consideration is that a Lock record should have a
listing of available keys. If it was me I think I would have an
AssignedTo
field in tblKeys:

tblKeys
KeyID (PK)
LockID (FK to tblLocks)
KeyCode (S2-A, etc., or whatever)
AssignedTo (FK to tblEmployees)
AssignedDate
Retired (Yes/No)

If I wanted to list people and the keys they hold I would use a query.

This is not necessarily the best design in that AssignedTo and
AssignedDate
are not really attributes of keys. The complexity here is that one
person
may be assigned many keys, but a key can be assigned to only one person.
Similarly, one lock may have many keys, but other than master keys a key
may
open only one lock. On the other hand, one person may open many locks,
and
a lock may be opened by many people. By the way, it just occurred to me
that if there may be several locks keyed to accept the same key you may
need
to add a LockLocation table related to tblLocks to take care of this
detail.
One solution here may be to have a LockPerson junction table (one person

many locks and vice versa). This would be the source for a subform on
the
Locks form. A list box could contain a listing of unassigned keys for
that
lock. The list box row source would have to be built as you go, since
the
available keys are always changing. When somebody needs to be assigned a
key you would go to the Lock form, see the listing of available keys, and
created a new LockPerson record that stores the KeyID, EmployeeID, and
maybe
AssignedDate and other details.
It may be worth your while to start a new thread on this specific topic.
All
you would need to say is that you have:
A Locks table containing the LockId, LockLocation, etc.
A Keys table containing KeyID (PK), LockID (FK), KeyCode, etc.
An Employee table

Explain that you understand a Lock may have many keys, and that a person
may
be assigned many keys. However, you are unsure how to store the
AssignedTo
information for Keys. Should it be in the Keys table? If not, how is
that
relationship modeled.

I suggest this because frankly I am unsure how best to proceed on this
point, and in a new thread you would attract the attention of very
experienced designers.

4. Create additional look-up tables: tblCampuses, tblWings and
tblLocationTypes.

Sounds good.

**********

"Aria" wrote in message
...
I think I may have a problem that I need to work through. We can discuss
this
when you have time. I just wanted to get this down before I lose track
and
start dealing with other issues. I think we are going to need to
re-visit
an
issue from the very first post: vault keys. Originally, we decided that
the
situation was unclear and dropped it. In looking through some of the
data
that I copied to help map my direction, I just noticed something that I
probably saw before but did not grab my attention as it has now.
During
the
re-key, among the many replacement keys made, one key was important
enough
to
be "assigned" to the vault. There are probably others, but that
happened
before my time so I am not aware of the previous history. This does
change
things a bit. I'm going to have to account for not only that key, but
all
of
the vault keys.

I have two trains of thought right now:

The first is that the vault key is a sub type key that will need its
own
table. I don't know about this because it doesn't seem to fit the model
of
a
sub type (at least not as far as I can see). It's not like the masters
which
are actually a different type of key. Their attributes are
significantly
different. Not so with the vault key; there's nothing special or
different
about them.

The second thought is that this is really a location type and will need
to
be included with tbllocations or is it tbllocationtypes. I'm still
working
on
this because I'm unsure right now. It does seem to fit the "where"
model
though.

Just throwing it out there...

--
Aria W.


"Aria" wrote:

I don't have much time to reply today, but I have noted a few things
inline.

Please, don't give it a second thought. I appreciate all of the
support
you
have both given me. I understand.

If you select the combo box, open the Property Sheet (with the tabs
for
Format, Data, etc.), select an event, click the three dots, click
Code
Builder, and click OK the name of the control will be filled in for
you
in
the code window. If you type it yourself you need the underscore.
I
think
that is so there are no spaces in the procedure name.

I'll check on that.

There's no definitive answer for that, but anything that involves
junction
tables is a lot to get your mind around if you are just starting.
Before
long, if it hasn't already happened, the need for junction tables,
and
how
to use them, will be clear in your mind. In your case there were a
number
of junction tables, and a situation that involved keys, locks,
people
to
whom the keys were issued, locations of the locks, campuses, and a
number of
other entities, with a variety of relationships between the
entities.

Yeah, no kidding. I started thinking about that because I was trying
to
avoid adding yet another junction table. I recall a previous
discussion
where
we decided that the room phone could go into tblLocations. That would
leave
district cell phone orphaned and I could not figure out where to put
it.
It
doesn't belong in tblLocations and doesn't belong in tblEmployees so I
figured why am I drawing the line at this junction table when there
are 5
others just like it. Oh well...c'est la vie! I keep looking at the
relationship diagram and I 'm concerned how I will manage all of this.
In
particular, what kind of form to design and whether I should have
another
subform for tbKleysRequests on frmEmployees. I'm trying not to borrow
trouble; one thing at a time.

What became of tblLocks? If one lock may have several keys, locks
are
the
top level.

"A lock can have several keys". There have been a number of turning
points
in this journey. You both have dropped statements that on the surface
seemed
inconsequential ,but in reality had a major impact. That is one thing
I
am
*never* going to forget. You made 3 on the mark statements in that
post.
tblLocks is still here. It*is* a junction table, correct? It sure
looks
like
one.
Suggestions still on the table:
1. Create tblLocations to replace tblRooms.
2. Create tblLocks to define the relationsip between keys and
locks.
There
should be a 2 field PK involving Key ID and LocationID.
3. Create Master Key table to account for the special attributes
of
Master
Keys.
4. Create additional look-up tables: tblCampuses, tblWings and
tblLocationTypes.

Questions/Comments:
1.Decision--Unbeknowst to you and Beetle, I was going to use a
natural key
for KeyID in tblKeys. Your statement about a possible re-key and
our
history
of such finally made me realize that this was a *lousy* idea from
the
beginning. I'm switching to autonumber.

There's nothing wrong with a natural key, depending on what it is.
With a
surrogate key such as autonumber the main thing is that the record
needs to
be unique for reasons apart from the autonumber field. If two
records
are
identical except for an artificial identifier then they are not
really
unique. The autonumber is a convenience, but cannot by itself
enforce
what
is known as a unique constraint.

Won't this cause a problem? With the re-key, they not only changed the
lock,
they changed the lock identifier. So if the key was previously, let's
say,
SA-2 , it may have been changed to XJ-3A after the re-key. If I used
this
as
my primary key, I would have thought this would be a nightmarish
situation.
No? If it happened once, there's always the possibility that it
*could*
happen again. Keys are lost pretty much on a weekly basis. What do you
thinK?
Do I need an inactive button for keys? I don't know exactly *how* this
would
work.

Let me know what you think about that and the master keys. Don't
concern
yourself if you don't have time. I have problems in the db that I need
to
straighten out. Thanks so much for your time Bruce.

--
Aria W.


"BruceM" wrote:

I don't have much time to reply today, but I have noted a few things
inline.

"Aria" wrote in message
...
I found the compile button. It was under commands so I added it to
the
toolbar. Thanks.

I will take a look at your questions, but you will need to sort
of
start
over with your descriptions, as I have not been following very
closely of
late. When you do so, list only the essential fields.

Not quite ready to list the table structures for this part
yet...still
stinging from the last time when they were all wrong. I just
basically
want
to think on post. Ask a few questions and have you weigh in on
where
I'm
going wrong. Are you Ok with that? I completely understand what
you
mean
as
far as having lost track. I have all my notes and posts and I
still
have
to
read up on what's going on and what transpired.

Questions unrelated to 2nd half of db:
1. When I input the programmng code for the AfterUpdate event, I
input
cboStaff_Lookup. The line highlighted in yellow said, "Private Sub
cboStaff_Lookup_ AfterUpdate () Was I supposed to input that final
underscore
after Lookup?


  #97  
Old July 17th, 2008, 08:36 PM posted to microsoft.public.access.gettingstarted
Aria
external usenet poster
 
Posts: 150
Default Still Struggling...

Here's the structure, mistakes and all:

tblKeys 1:M tblMasterKeys
KeyID PK (Autonumber)
KeyName
MstrKeyID (FK, number long integer to tblMasterKeys)

tblMasterKeys
MstrKeyID PK (Autonumber)
MstrKeyName

tblKeysEmployees M:M tblEmployees
KeyID (1/2 PK, FK to tblKeys, number, l.i.)
EmpID (1/2 PK, FK to tblEmployees, #, l.i.)
AllowedtoRetain Yes/No
Approvedby
DateIssued Date/Time
DateLost Date/Time
DateRtrnd Date/Time

tblKeysRequests 1:M tblKeysEmployees
RequestID PK (Autonumber)
KeyID FK, #, l.i. to tblKeysEmployees
QtyRqstd
DateRqstd Date/Time
DateIssued Date/Time
DateIssued (Hmmm...I just noticed that this is the same as tblKeysEmployees)
Funny how you can gloss right over things.
Comments

tblLocks (I thought this was a junction table but now I don't know)
KeyID PK/FK
LocationID PK/FK

tblLocations 1:M tblLocks
LocationID PK (Autonumber)
LocationTypeID FK to tblLocationTypes
LocationName
Remarks

tblLocationTypes 1:M tblLocations
LocationTypeID PK (Autonumber)
LocationType

tblCampuses 1:M tblLocations
CampusID PK (Autonumber)
CampusName

tblWings 1:M tblLocations
WingsID PK (Autonumber)
WingName

So I think tblKeysEmployees defines the relationship between keys and
employees.

Regarding other parts of your previous post:

The complexity here is that one person may be assigned many keys, but a key can be assigned to only one person.


No, this is not quite true. One key can be assigned to one or many people.

One solution here may be to have a LockPerson junction table (one person many locks and vice versa).


....*another* junction table?! Please...is there any way around this?


This would be the source for a subform on the Locks form. A list box could contain a listing of unassigned keys for that lock. The list box row source would have to be built as you go, since the available keys are always changing. When somebody needs to be assigned a key you would go to the Lock form, see the listing of available keys, and created a new LockPerson record that stores the KeyID, EmployeeID, and maybe AssignedDate and other details.


It would be nice to have a list of unassigned keys but...it's a little
overwhelming right now. This just keeps growing and growing. I'm already onto
page 2 for printing the relationship diagram. Let me live with this for
awhile. I know yesterday I posted, "Oh well, c'est la vie" as far as junction
tables but today I can't deal with another junction table.

BTW:

tblKeys
KeyID (PK)
LockID (FK to tblLocks)
KeyCode (S2-A, etc., or whatever)
AssignedTo (FK to tblEmployees)
AssignedDate
Retired (Yes/No)

I like the field name KeyCode. I'm not so sure about the Retired (Yes/No)
field although that does have to be taken into account. I will probably end
up doing it that way. Let me think about it some more.

Let me know if this structure resolves *any* of the issues we have.
--
Aria W.


"BruceM" wrote:

Is the vault key just like any other key for a particular lock, except that
it is in the vault? If so, is the vault copy essentially a clean copy to be
used as the master for additional copies? If so, you can identify the valut
key either by an extra field (maybe a Yes/No Vault field) in tblKeys, or you
can "assign" the key to the vault just as you would assign it to a person.
To do this you could add (Vault) to the top of the drop-down list of
Employees to whom keys are issued, similar to the way some drop-down lists
show (All) at the top. I won't go too far down that road until I hear back
from you.

Regarding the Locks table, I don't think it would be a junction table. A
lock is an entity with certain characteristics such as brand, location, date
installed, and so forth. One Lock can have many keys. Iff Master Keys are
included in the thinking, one Key can be for many Locks, but in this case
the junction table would be tblKeyLock or something like that.

Regarding tblKey, I expect there should be a Lost field or something like
that. There is no need to keep an active listing of keys nobody can find.
Regarding the question of natural key or surrogate key (any "artificial
identifier", including autonumber), it really doesn't matter as long as the
"natural" number such as SA-2 is used once for one physical (metal) key, and
never used again. If you are not sure this is the case, autonumber would be
a simpler choice as the PK. The same idea comes into play with the Lock
identifier, I expect. If they change the lock in such a way that the old
keys can be used you will need to update the FK of those keys so that they
are associated with the new lock.

From an earlier post you wrote:

Suggestions still on the table:
1. Create tblLocations to replace tblRooms

Sounds like a good idea
..
2. Create tblLocks to define the relationsip between keys and locks. There
should be a 2 field PK involving Key ID and LocationID.

Already discussed. Let me know if something is unclear, or if I am missing
something

3. Create Master Key table to account for the special attributes of Master
Keys.

One possibility is to see the situation as One Lock Many Keys and One Key
Many Locks, in which tblKeyLock is needed to resolve the relationship for

all locks and all keys. However, I think a separate table for MasterKeys
and a junction table tblKeyLock would be simpler to manage. If you are
looking at a Lock record you would have a subform listing the ordinary keys
and the person to whom they are assigned (some may not be assigned at all, I
expect). One Lock Many Keys, so there is a 1:M between tblLock and
tblKey, and the subform is based on tblKey. Another subform based on
tblKeyLock could list the master key holders.
One lock could have keys assigned to many people, and each person could be
assigned keys. Another consideration is that a Lock record should have a
listing of available keys. If it was me I think I would have an AssignedTo
field in tblKeys:

tblKeys
KeyID (PK)
LockID (FK to tblLocks)
KeyCode (S2-A, etc., or whatever)
AssignedTo (FK to tblEmployees)
AssignedDate
Retired (Yes/No)

If I wanted to list people and the keys they hold I would use a query.

This is not necessarily the best design in that AssignedTo and AssignedDate
are not really attributes of keys. The complexity here is that one person
may be assigned many keys, but a key can be assigned to only one person.
Similarly, one lock may have many keys, but other than master keys a key may
open only one lock. On the other hand, one person may open many locks, and
a lock may be opened by many people. By the way, it just occurred to me
that if there may be several locks keyed to accept the same key you may need
to add a LockLocation table related to tblLocks to take care of this detail.
One solution here may be to have a LockPerson junction table (one person
many locks and vice versa). This would be the source for a subform on the
Locks form. A list box could contain a listing of unassigned keys for that
lock. The list box row source would have to be built as you go, since the
available keys are always changing. When somebody needs to be assigned a
key you would go to the Lock form, see the listing of available keys, and
created a new LockPerson record that stores the KeyID, EmployeeID, and maybe
AssignedDate and other details.
It may be worth your while to start a new thread on this specific topic. All
you would need to say is that you have:
A Locks table containing the LockId, LockLocation, etc.
A Keys table containing KeyID (PK), LockID (FK), KeyCode, etc.
An Employee table

Explain that you understand a Lock may have many keys, and that a person may
be assigned many keys. However, you are unsure how to store the AssignedTo
information for Keys. Should it be in the Keys table? If not, how is that
relationship modeled.

I suggest this because frankly I am unsure how best to proceed on this
point, and in a new thread you would attract the attention of very
experienced designers.

4. Create additional look-up tables: tblCampuses, tblWings and
tblLocationTypes.

Sounds good.

**********

"Aria" wrote in message
...
I think I may have a problem that I need to work through. We can discuss
this
when you have time. I just wanted to get this down before I lose track and
start dealing with other issues. I think we are going to need to re-visit
an
issue from the very first post: vault keys. Originally, we decided that
the
situation was unclear and dropped it. In looking through some of the data
that I copied to help map my direction, I just noticed something that I
probably saw before but did not grab my attention as it has now. During
the
re-key, among the many replacement keys made, one key was important enough
to
be "assigned" to the vault. There are probably others, but that happened
before my time so I am not aware of the previous history. This does change
things a bit. I'm going to have to account for not only that key, but all
of
the vault keys.

I have two trains of thought right now:

The first is that the vault key is a sub type key that will need its own
table. I don't know about this because it doesn't seem to fit the model of
a
sub type (at least not as far as I can see). It's not like the masters
which
are actually a different type of key. Their attributes are significantly
different. Not so with the vault key; there's nothing special or different
about them.

The second thought is that this is really a location type and will need to
be included with tbllocations or is it tbllocationtypes. I'm still working
on
this because I'm unsure right now. It does seem to fit the "where" model
though.

Just throwing it out there...

--
Aria W.


"Aria" wrote:

I don't have much time to reply today, but I have noted a few things
inline.

Please, don't give it a second thought. I appreciate all of the support
you
have both given me. I understand.

If you select the combo box, open the Property Sheet (with the tabs for
Format, Data, etc.), select an event, click the three dots, click Code
Builder, and click OK the name of the control will be filled in for you
in
the code window. If you type it yourself you need the underscore. I
think
that is so there are no spaces in the procedure name.

I'll check on that.

There's no definitive answer for that, but anything that involves
junction
tables is a lot to get your mind around if you are just starting.
Before
long, if it hasn't already happened, the need for junction tables, and
how
to use them, will be clear in your mind. In your case there were a
number
of junction tables, and a situation that involved keys, locks, people
to
whom the keys were issued, locations of the locks, campuses, and a
number of
other entities, with a variety of relationships between the entities.

Yeah, no kidding. I started thinking about that because I was trying to
avoid adding yet another junction table. I recall a previous discussion
where
we decided that the room phone could go into tblLocations. That would
leave
district cell phone orphaned and I could not figure out where to put it.
It
doesn't belong in tblLocations and doesn't belong in tblEmployees so I
figured why am I drawing the line at this junction table when there are 5
others just like it. Oh well...c'est la vie! I keep looking at the
relationship diagram and I 'm concerned how I will manage all of this. In
particular, what kind of form to design and whether I should have
another
subform for tbKleysRequests on frmEmployees. I'm trying not to borrow
trouble; one thing at a time.

What became of tblLocks? If one lock may have several keys, locks are
the
top level.

"A lock can have several keys". There have been a number of turning
points
in this journey. You both have dropped statements that on the surface
seemed
inconsequential ,but in reality had a major impact. That is one thing I
am
*never* going to forget. You made 3 on the mark statements in that post.
tblLocks is still here. It*is* a junction table, correct? It sure looks
like
one.
Suggestions still on the table:
1. Create tblLocations to replace tblRooms.
2. Create tblLocks to define the relationsip between keys and locks.
There
should be a 2 field PK involving Key ID and LocationID.
3. Create Master Key table to account for the special attributes of
Master
Keys.
4. Create additional look-up tables: tblCampuses, tblWings and
tblLocationTypes.

Questions/Comments:
1.Decision--Unbeknowst to you and Beetle, I was going to use a
natural key
for KeyID in tblKeys. Your statement about a possible re-key and our
history
of such finally made me realize that this was a *lousy* idea from the
beginning. I'm switching to autonumber.

There's nothing wrong with a natural key, depending on what it is.
With a
surrogate key such as autonumber the main thing is that the record
needs to
be unique for reasons apart from the autonumber field. If two records
are
identical except for an artificial identifier then they are not really
unique. The autonumber is a convenience, but cannot by itself enforce
what
is known as a unique constraint.

Won't this cause a problem? With the re-key, they not only changed the
lock,
they changed the lock identifier. So if the key was previously, let's
say,
SA-2 , it may have been changed to XJ-3A after the re-key. If I used this
as
my primary key, I would have thought this would be a nightmarish
situation.
No? If it happened once, there's always the possibility that it *could*
happen again. Keys are lost pretty much on a weekly basis. What do you
thinK?
Do I need an inactive button for keys? I don't know exactly *how* this
would
work.

Let me know what you think about that and the master keys. Don't concern
yourself if you don't have time. I have problems in the db that I need to
straighten out. Thanks so much for your time Bruce.

--
Aria W.


"BruceM" wrote:

I don't have much time to reply today, but I have noted a few things
inline.

"Aria" wrote in message
...
I found the compile button. It was under commands so I added it to the
toolbar. Thanks.

I will take a look at your questions, but you will need to sort of
start
over with your descriptions, as I have not been following very
closely of
late. When you do so, list only the essential fields.

Not quite ready to list the table structures for this part
yet...still
stinging from the last time when they were all wrong. I just
basically
want
to think on post. Ask a few questions and have you weigh in on where
I'm
going wrong. Are you Ok with that? I completely understand what you
mean
as
far as having lost track. I have all my notes and posts and I still
have
to
read up on what's going on and what transpired.

Questions unrelated to 2nd half of db:
1. When I input the programmng code for the AfterUpdate event, I
input
cboStaff_Lookup. The line highlighted in yellow said, "Private Sub
cboStaff_Lookup_ AfterUpdate () Was I supposed to input that final
underscore
after Lookup?

  #98  
Old July 18th, 2008, 08:22 PM posted to microsoft.public.access.gettingstarted
BruceM[_2_]
external usenet poster
 
Posts: 1,763
Default Still Struggling...

This will probably be my last posting for a while, as I will be away next
week and need to finish up a few things before I go.

"Aria" wrote in message
...
Here's the structure, mistakes and all:

tblKeys 1:M tblMasterKeys
KeyID PK (Autonumber)
KeyName
MstrKeyID (FK, number long integer to tblMasterKeys)

I still think the relationship is between keys and locks, not keys and other
keys. A key opens one lock. Ignoring master keys for the moment, you have
One Lock : Many Keys, so LockID is a FK in tblKeys.

A master key opens several locks. One master key can open several locks,
and each lock can be opened by several different keys including the master
key. If there is to be a junction table I think it would be between locks
and keys. Except for the master key this is a one-to-many relationship, but
making it many-to-many even though the first "many" is applied infrequently
is OK. There may be other ways to model this relationship, but this is one
that occurs to me.

tblMasterKeys
MstrKeyID PK (Autonumber)
MstrKeyName


tblKeysEmployees M:M tblEmployees
KeyID (1/2 PK, FK to tblKeys, number, l.i.)
EmpID (1/2 PK, FK to tblEmployees, #, l.i.)
AllowedtoRetain Yes/No
Approvedby
DateIssued Date/Time
DateLost Date/Time
DateRtrnd Date/Time


The question here is how the lock fits into the picture. If you may want to
see a listing of who can open a particular lock you need a way to associate
locks with employees.


tblKeysRequests 1:M tblKeysEmployees
RequestID PK (Autonumber)
KeyID FK, #, l.i. to tblKeysEmployees
QtyRqstd
DateRqstd Date/Time
DateIssued Date/Time
DateIssued (Hmmm...I just noticed that this is the same as
tblKeysEmployees)
Funny how you can gloss right over things.
Comments

tblLocks (I thought this was a junction table but now I don't know)
KeyID PK/FK
LocationID PK/FK


It is not a junction table that I can see. One lock has many keys, not the
other way around (except for master keys). In the case of a master key it
is one of the many keys that can open a lock.

tblLocations 1:M tblLocks
LocationID PK (Autonumber)
LocationTypeID FK to tblLocationTypes
LocationName
Remarks

tblLocationTypes 1:M tblLocations
LocationTypeID PK (Autonumber)
LocationType

tblCampuses 1:M tblLocations
CampusID PK (Autonumber)
CampusName

tblWings 1:M tblLocations
WingsID PK (Autonumber)
WingName

You may be cutting it a bit fine here. I have to disagree with Sean that
all fields need to be filled in. It happens all the time that a Middle
Initial field is not filled in, for instance. For another example,
Apartment Number does not apply if the person lives in a house, but I see no
reason in a database of this scale (i.e. not super large) to separate this
datum into its own table. Find a way to identify where the lock is located.
A lock will be located on a campus, and maybe in a building (unless it is an
outdoors lock to an athletic field gate or something). If a building, it
may have wings, or maybe not. You can use a lookup table to insert a value
into, say, the Wing or Building field in the Locks table. You can even
limit the Wing listing to just the Wings in the selected Building. However,
you may not need to involve these lookup tables into relationships.


So I think tblKeysEmployees defines the relationship between keys and
employees.

Regarding other parts of your previous post:

The complexity here is that one person may be assigned many keys, but a
key can be assigned to only one person.


No, this is not quite true. One key can be assigned to one or many people.

One solution here may be to have a LockPerson junction table (one person
many locks and vice versa).


...*another* junction table?! Please...is there any way around this?


This is in place of the KeyEmployee junction table, which I maintain is not
exactly the relationship you should have.


This would be the source for a subform on the Locks form. A list box could
contain a listing of unassigned keys for that lock. The list box row
source would have to be built as you go, since the available keys are
always changing. When somebody needs to be assigned a key you would go to
the Lock form, see the listing of available keys, and created a new
LockPerson record that stores the KeyID, EmployeeID, and maybe
AssignedDate and other details.


It would be nice to have a list of unassigned keys but...it's a little
overwhelming right now. This just keeps growing and growing. I'm already
onto
page 2 for printing the relationship diagram. Let me live with this for
awhile. I know yesterday I posted, "Oh well, c'est la vie" as far as
junction
tables but today I can't deal with another junction table.


You would use SQL to insert a list into a list box, or maybe into a
continuous form. You do not need another table. The data are already there
(or will be when this is all set up).

BTW:

tblKeys
KeyID (PK)
LockID (FK to tblLocks)
KeyCode (S2-A, etc., or whatever)
AssignedTo (FK to tblEmployees)
AssignedDate
Retired (Yes/No)

I like the field name KeyCode. I'm not so sure about the Retired (Yes/No)
field although that does have to be taken into account. I will probably
end
up doing it that way. Let me think about it some more.


I meant Retired to refer to the key, in case that is not clear. The point
is that if a key is lost or damaged or worn out the Retired field can be
used to exclude it from a listing of available keys.

Let me know if this structure resolves *any* of the issues we have.
--
Aria W.


Perhaps Sean will have some further insight, and perhaps he and I are not at
cross purposes. I repeat that I think it will be a good thing to take what
you have and start another thread. I would have asked some questions of the
group by now, as I am uncertain in some cases how to model this situation.
Instead I have been stretching my mind and my capabilities trying to figure
this out. It has been good practice, but I am about at the limit of what I
can suggest with confidence.

I will check in again, or search for other threads from you, when I return.
In the meantime, best of luck. I am confident you will get this figured
out, even if you doubt it from time to time.



"BruceM" wrote:

Is the vault key just like any other key for a particular lock, except
that
it is in the vault? If so, is the vault copy essentially a clean copy to
be
used as the master for additional copies? If so, you can identify the
valut
key either by an extra field (maybe a Yes/No Vault field) in tblKeys, or
you
can "assign" the key to the vault just as you would assign it to a
person.
To do this you could add (Vault) to the top of the drop-down list of
Employees to whom keys are issued, similar to the way some drop-down
lists
show (All) at the top. I won't go too far down that road until I hear
back
from you.

Regarding the Locks table, I don't think it would be a junction table. A
lock is an entity with certain characteristics such as brand, location,
date
installed, and so forth. One Lock can have many keys. Iff Master Keys
are
included in the thinking, one Key can be for many Locks, but in this case
the junction table would be tblKeyLock or something like that.

Regarding tblKey, I expect there should be a Lost field or something like
that. There is no need to keep an active listing of keys nobody can
find.
Regarding the question of natural key or surrogate key (any "artificial
identifier", including autonumber), it really doesn't matter as long as
the
"natural" number such as SA-2 is used once for one physical (metal) key,
and
never used again. If you are not sure this is the case, autonumber would
be
a simpler choice as the PK. The same idea comes into play with the Lock
identifier, I expect. If they change the lock in such a way that the old
keys can be used you will need to update the FK of those keys so that
they
are associated with the new lock.

From an earlier post you wrote:

Suggestions still on the table:
1. Create tblLocations to replace tblRooms

Sounds like a good idea
..
2. Create tblLocks to define the relationsip between keys and locks.
There
should be a 2 field PK involving Key ID and LocationID.

Already discussed. Let me know if something is unclear, or if I am
missing
something

3. Create Master Key table to account for the special attributes of
Master
Keys.

One possibility is to see the situation as One Lock Many Keys and One
Key
Many Locks, in which tblKeyLock is needed to resolve the relationship

for
all locks and all keys. However, I think a separate table for MasterKeys
and a junction table tblKeyLock would be simpler to manage. If you are
looking at a Lock record you would have a subform listing the ordinary
keys
and the person to whom they are assigned (some may not be assigned at
all, I
expect). One Lock Many Keys, so there is a 1:M between tblLock and
tblKey, and the subform is based on tblKey. Another subform based on
tblKeyLock could list the master key holders.
One lock could have keys assigned to many people, and each person could
be
assigned keys. Another consideration is that a Lock record should have a
listing of available keys. If it was me I think I would have an
AssignedTo
field in tblKeys:

tblKeys
KeyID (PK)
LockID (FK to tblLocks)
KeyCode (S2-A, etc., or whatever)
AssignedTo (FK to tblEmployees)
AssignedDate
Retired (Yes/No)

If I wanted to list people and the keys they hold I would use a query.

This is not necessarily the best design in that AssignedTo and
AssignedDate
are not really attributes of keys. The complexity here is that one
person
may be assigned many keys, but a key can be assigned to only one person.
Similarly, one lock may have many keys, but other than master keys a key
may
open only one lock. On the other hand, one person may open many locks,
and
a lock may be opened by many people. By the way, it just occurred to me
that if there may be several locks keyed to accept the same key you may
need
to add a LockLocation table related to tblLocks to take care of this
detail.
One solution here may be to have a LockPerson junction table (one person

many locks and vice versa). This would be the source for a subform on
the
Locks form. A list box could contain a listing of unassigned keys for
that
lock. The list box row source would have to be built as you go, since
the
available keys are always changing. When somebody needs to be assigned a
key you would go to the Lock form, see the listing of available keys, and
created a new LockPerson record that stores the KeyID, EmployeeID, and
maybe
AssignedDate and other details.
It may be worth your while to start a new thread on this specific topic.
All
you would need to say is that you have:
A Locks table containing the LockId, LockLocation, etc.
A Keys table containing KeyID (PK), LockID (FK), KeyCode, etc.
An Employee table

Explain that you understand a Lock may have many keys, and that a person
may
be assigned many keys. However, you are unsure how to store the
AssignedTo
information for Keys. Should it be in the Keys table? If not, how is
that
relationship modeled.

I suggest this because frankly I am unsure how best to proceed on this
point, and in a new thread you would attract the attention of very
experienced designers.

4. Create additional look-up tables: tblCampuses, tblWings and
tblLocationTypes.

Sounds good.

**********

"Aria" wrote in message
...
I think I may have a problem that I need to work through. We can discuss
this
when you have time. I just wanted to get this down before I lose track
and
start dealing with other issues. I think we are going to need to
re-visit
an
issue from the very first post: vault keys. Originally, we decided that
the
situation was unclear and dropped it. In looking through some of the
data
that I copied to help map my direction, I just noticed something that I
probably saw before but did not grab my attention as it has now.
During
the
re-key, among the many replacement keys made, one key was important
enough
to
be "assigned" to the vault. There are probably others, but that
happened
before my time so I am not aware of the previous history. This does
change
things a bit. I'm going to have to account for not only that key, but
all
of
the vault keys.

I have two trains of thought right now:

The first is that the vault key is a sub type key that will need its
own
table. I don't know about this because it doesn't seem to fit the model
of
a
sub type (at least not as far as I can see). It's not like the masters
which
are actually a different type of key. Their attributes are
significantly
different. Not so with the vault key; there's nothing special or
different
about them.

The second thought is that this is really a location type and will need
to
be included with tbllocations or is it tbllocationtypes. I'm still
working
on
this because I'm unsure right now. It does seem to fit the "where"
model
though.

Just throwing it out there...

--
Aria W.


"Aria" wrote:

I don't have much time to reply today, but I have noted a few things
inline.

Please, don't give it a second thought. I appreciate all of the
support
you
have both given me. I understand.

If you select the combo box, open the Property Sheet (with the tabs
for
Format, Data, etc.), select an event, click the three dots, click
Code
Builder, and click OK the name of the control will be filled in for
you
in
the code window. If you type it yourself you need the underscore.
I
think
that is so there are no spaces in the procedure name.

I'll check on that.

There's no definitive answer for that, but anything that involves
junction
tables is a lot to get your mind around if you are just starting.
Before
long, if it hasn't already happened, the need for junction tables,
and
how
to use them, will be clear in your mind. In your case there were a
number
of junction tables, and a situation that involved keys, locks,
people
to
whom the keys were issued, locations of the locks, campuses, and a
number of
other entities, with a variety of relationships between the
entities.

Yeah, no kidding. I started thinking about that because I was trying
to
avoid adding yet another junction table. I recall a previous
discussion
where
we decided that the room phone could go into tblLocations. That would
leave
district cell phone orphaned and I could not figure out where to put
it.
It
doesn't belong in tblLocations and doesn't belong in tblEmployees so I
figured why am I drawing the line at this junction table when there
are 5
others just like it. Oh well...c'est la vie! I keep looking at the
relationship diagram and I 'm concerned how I will manage all of this.
In
particular, what kind of form to design and whether I should have
another
subform for tbKleysRequests on frmEmployees. I'm trying not to borrow
trouble; one thing at a time.

What became of tblLocks? If one lock may have several keys, locks
are
the
top level.

"A lock can have several keys". There have been a number of turning
points
in this journey. You both have dropped statements that on the surface
seemed
inconsequential ,but in reality had a major impact. That is one thing
I
am
*never* going to forget. You made 3 on the mark statements in that
post.
tblLocks is still here. It*is* a junction table, correct? It sure
looks
like
one.
Suggestions still on the table:
1. Create tblLocations to replace tblRooms.
2. Create tblLocks to define the relationsip between keys and
locks.
There
should be a 2 field PK involving Key ID and LocationID.
3. Create Master Key table to account for the special attributes
of
Master
Keys.
4. Create additional look-up tables: tblCampuses, tblWings and
tblLocationTypes.

Questions/Comments:
1.Decision--Unbeknowst to you and Beetle, I was going to use a
natural key
for KeyID in tblKeys. Your statement about a possible re-key and
our
history
of such finally made me realize that this was a *lousy* idea from
the
beginning. I'm switching to autonumber.

There's nothing wrong with a natural key, depending on what it is.
With a
surrogate key such as autonumber the main thing is that the record
needs to
be unique for reasons apart from the autonumber field. If two
records
are
identical except for an artificial identifier then they are not
really
unique. The autonumber is a convenience, but cannot by itself
enforce
what
is known as a unique constraint.

Won't this cause a problem? With the re-key, they not only changed the
lock,
they changed the lock identifier. So if the key was previously, let's
say,
SA-2 , it may have been changed to XJ-3A after the re-key. If I used
this
as
my primary key, I would have thought this would be a nightmarish
situation.
No? If it happened once, there's always the possibility that it
*could*
happen again. Keys are lost pretty much on a weekly basis. What do you
thinK?
Do I need an inactive button for keys? I don't know exactly *how* this
would
work.

Let me know what you think about that and the master keys. Don't
concern
yourself if you don't have time. I have problems in the db that I need
to
straighten out. Thanks so much for your time Bruce.

--
Aria W.


"BruceM" wrote:

I don't have much time to reply today, but I have noted a few things
inline.

"Aria" wrote in message
...
I found the compile button. It was under commands so I added it to
the
toolbar. Thanks.

I will take a look at your questions, but you will need to sort
of
start
over with your descriptions, as I have not been following very
closely of
late. When you do so, list only the essential fields.

Not quite ready to list the table structures for this part
yet...still
stinging from the last time when they were all wrong. I just
basically
want
to think on post. Ask a few questions and have you weigh in on
where
I'm
going wrong. Are you Ok with that? I completely understand what
you
mean
as
far as having lost track. I have all my notes and posts and I
still
have
to
read up on what's going on and what transpired.

Questions unrelated to 2nd half of db:
1. When I input the programmng code for the AfterUpdate event, I
input
cboStaff_Lookup. The line highlighted in yellow said, "Private Sub
cboStaff_Lookup_ AfterUpdate () Was I supposed to input that final
underscore
after Lookup?


 




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