Primary Keys

"Terry Kreft" wrote in
:

But that's David's choice whether he supplies that or not, you are
free to make any inference you like from his failure to reply but
if you post that inference then you leave yourself open to
challenge. Your concluding remark was not a reasonable conclusion
from David's refusal to answer.

The reason I won't is that it would be rehashing material that's
been posted every time the topic of natural vs. surrogate keys has
come up. I don't see any point in posting something that would just
duplicate information that's been posted here dozens of times.

--
David W. Fenton http://www.dfenton.com/
usenet at dfenton dot com http://www.dfenton.com/DFA/

"Jamie Collins" wrote in
oups.com:

To get a clustered index in Jet, I must leverage the PRIMARY KEY
syntax.

You mis-spelled "mis-use PK syntax."

--
David W. Fenton http://www.dfenton.com/
usenet at dfenton dot com http://www.dfenton.com/DFA/

"Jamie Collins" wrote in
oups.com:

I hope you can now understand my point and that any reply is a lot
less confused/confusing than your previous one.

I'm done here. You're an idiot.

--
David W. Fenton http://www.dfenton.com/
usenet at dfenton dot com http://www.dfenton.com/DFA/

David W. Fenton wrote:
The reason I won't is that it would be rehashing material that's
been posted every time the topic of natural vs. surrogate keys has
come up. I don't see any point in posting something that would just
duplicate information that's been posted here dozens of times.

My question does not relate to natural vs. surrogate keys.

I want to know the difference in Jet between a column constrained as
NOT NULL UNIQUE and PRIMARY KEY. If there is existing subject matter on
this issue, please provide me with a link.

Jamie.

--

Terry Kreft wrote:
that's David's choice whether he supplies that or not, you are free to
make any inference you like from his failure to reply but if you post that
inference then you leave yourself open to challenge. Your concluding remark
was not a reasonable conclusion from David's refusal to answer.

My intention is to discourage readers from inferring anything from
someone who makes an assertion without reasoning.

Terry, Take another look. Could it be the case that David W. Fenton is
a subtle kind of troll: adds only snippets of information, does not
elaborate, posts intentionally confusing replies, puts more time and
effort into being rude than advancing the debate, calls everyone an
idiot before disappearing? My advice: don't try and do logic with a
troll.

Jamie.

--

I think there are lots of people, in CDMA especially, who display troll-like
attributes on occasion although on the whole I would not describe them as
trolls.

There are times when resorting to troll-like behaviour seems to be the only
way to get through to some people.


--

Terry Kreft


"Jamie Collins" wrote in message
ups.com...

Terry Kreft wrote:
that's David's choice whether he supplies that or not, you are free to
make any inference you like from his failure to reply but if you post
that
inference then you leave yourself open to challenge. Your concluding
remark
was not a reasonable conclusion from David's refusal to answer.

My intention is to discourage readers from inferring anything from
someone who makes an assertion without reasoning.

Terry, Take another look. Could it be the case that David W. Fenton is
a subtle kind of troll: adds only snippets of information, does not
elaborate, posts intentionally confusing replies, puts more time and
effort into being rude than advancing the debate, calls everyone an
idiot before disappearing? My advice: don't try and do logic with a
troll.

Jamie.

--

David W. Fenton wrote:
retract the allegation.

OK, I retract the allegation. David, you are not bluffing. You have
your list of differences between NOT NULL UNIQUE and PRIMARY KEY. I am
truly sorry my underhand tactics have not resulted in you posting that
list here. While I'm about it, you are not a you troll; your point
about concurrency was welcome.

I hope I've shown I'll do much to get the correct information,
including being pleasant.

Jamie.

--

Larry Linson wrote:
David does not "tolerate fools gladly" and his words are sometimes sharper
than I might write, but he "knows his stuff" when it comes to Access and
Jet.

Consider these tables:

CREATE TABLE Test (
col1 INTEGER NOT NULL,
col2 INTEGER NOT NULL,
PRIMARY KEY (col1, col2)
);

CREATE TABLE Test (
col1 INTEGER NOT NULL,
col2 INTEGER NOT NULL,
UNIQUE (col1, col2)
);

AFAIK in Jet terms the only difference differences between the tables
is that the one with the PRIMARY KEY constraint will cluster on (col1,
col2) whereas the one with the UNIQUE constraint will not (i.e. retain
date/time inserted order).

There is a further point:

CREATE TABLE Test (
col1 INTEGER NOT NULL,
col2 INTEGER,
PRIMARY KEY (col1, col2)
);

CREATE TABLE Test (
col1 INTEGER NOT NULL,
col2 INTEGER,
UNIQUE (col1, col2)
);

The difference here is that although the one with the PRIMARY KEY
constraint can be created, no row where col2 is NULL can be inserted.

I do not think there are any further differences. If anyone thinks
there are, could they please post them here.

TIA,
Jamie.

--

On Tue, 18 Jul 2006 10:35:13 +0100, "Terry Kreft" wrote:


I think there are lots of people, in CDMA especially, who display troll-like
attributes on occasion although on the whole I would not describe them as
trolls.

There are times when resorting to troll-like behaviour seems to be the only
way to get through to some people.

CDMA hardly holds the record for troll-like behaviour!

polite person wrote:

CDMA hardly holds the record for troll-like behaviour!

It's probably one of the best groups out there in usenet for generally
good rapport. A few notable exceptions notwithstanding.

--
Tim http://www.ucs.mun.ca/~tmarshal/
^o
/#) "Burp-beep, burp-beep, burp-beep?" - Quaker Jake
/^^ "Whatcha doin?" - Ditto "TIM-MAY!!" - Me