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#1
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I would like to make a query on a table on one field to 'sum' or 'max' the
field based on 'if' another field is null or not. Any idea on how I would go about this? Please be generous as I am not an Access expert :-) -- Barry |
#2
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Type the expression you want in the Field row in query design, e.g.:
IIf([CreditDate] Is Not Null, [CreditAmount], 0) You can then Sum or choose the Max of this value in the Total row. (Depress the Total icon on the toolbar if you don't see the Total row in query design.) -- Allen Browne - Microsoft MVP. Perth, Western Australia Tips for Access users - http://allenbrowne.com/tips.html Reply to group, rather than allenbrowne at mvps dot org. "Barry" wrote in message ... I would like to make a query on a table on one field to 'sum' or 'max' the field based on 'if' another field is null or not. Any idea on how I would go about this? Please be generous as I am not an Access expert :-) -- Barry |
#3
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I think you need to provide some context and sample data as well as desired
results. Sum and Max work against a group of records while "another field is null" seems to work against just a single record. -- Duane Hookom Microsoft Access MVP "Barry" wrote: I would like to make a query on a table on one field to 'sum' or 'max' the field based on 'if' another field is null or not. Any idea on how I would go about this? Please be generous as I am not an Access expert :-) -- Barry |
#4
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Yes, Duane you are right...the null field is based on each record, but I
would like the statement to sum the values [Result] if there are any rows of null values in the other field [Qual]. Example: 'Result' 'Qual' 'Lab_id' 1 1111 2 J 1111 3 1111 4 2222 ---------------------------- 4 1111 ('Result' being equal to four because the 'Result' "1" and "3" both have 'Qual' as "null" and the same 'Lab_id' as "1111"). The [Lab_id] is the field I want the query to sort the data, and calculation, by. Is there any way to do this without specifying specific values in the statement, but rather all values that are the same? -- Barry Guidry "Duane Hookom" wrote: I think you need to provide some context and sample data as well as desired results. Sum and Max work against a group of records while "another field is null" seems to work against just a single record. -- Duane Hookom Microsoft Access MVP "Barry" wrote: I would like to make a query on a table on one field to 'sum' or 'max' the field based on 'if' another field is null or not. Any idea on how I would go about this? Please be generous as I am not an Access expert :-) -- Barry |
#5
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If I understand correctly, Allen Browne's suggestion should work. It's
difficult to determine since you included a data record 4... ...2222 that seems to be ignored and the "4" is the same as the result you are expecting from the Result column. -- Duane Hookom Microsoft Access MVP "Barry" wrote: Yes, Duane you are right...the null field is based on each record, but I would like the statement to sum the values [Result] if there are any rows of null values in the other field [Qual]. Example: 'Result' 'Qual' 'Lab_id' 1 1111 2 J 1111 3 1111 4 2222 ---------------------------- 4 1111 ('Result' being equal to four because the 'Result' "1" and "3" both have 'Qual' as "null" and the same 'Lab_id' as "1111"). The [Lab_id] is the field I want the query to sort the data, and calculation, by. Is there any way to do this without specifying specific values in the statement, but rather all values that are the same? -- Barry Guidry "Duane Hookom" wrote: I think you need to provide some context and sample data as well as desired results. Sum and Max work against a group of records while "another field is null" seems to work against just a single record. -- Duane Hookom Microsoft Access MVP "Barry" wrote: I would like to make a query on a table on one field to 'sum' or 'max' the field based on 'if' another field is null or not. Any idea on how I would go about this? Please be generous as I am not an Access expert :-) -- Barry |
#6
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Yes, thanks to Allen Browne, his suggestion, IIf([CreditDate] Is Not Null,
[CreditAmount], 0) You can then Sum or choose the Max of this value in the Total row, does work to do one or the other (either sum or max). But, what I am trying to do is to do a combination of the two (both sum or max) in one expression, based on whether or not the other field contains a null value or not. -- Barry Guidry "Duane Hookom" wrote: If I understand correctly, Allen Browne's suggestion should work. It's difficult to determine since you included a data record 4... ...2222 that seems to be ignored and the "4" is the same as the result you are expecting from the Result column. -- Duane Hookom Microsoft Access MVP "Barry" wrote: Yes, Duane you are right...the null field is based on each record, but I would like the statement to sum the values [Result] if there are any rows of null values in the other field [Qual]. Example: 'Result' 'Qual' 'Lab_id' 1 1111 2 J 1111 3 1111 4 2222 ---------------------------- 4 1111 ('Result' being equal to four because the 'Result' "1" and "3" both have 'Qual' as "null" and the same 'Lab_id' as "1111"). The [Lab_id] is the field I want the query to sort the data, and calculation, by. Is there any way to do this without specifying specific values in the statement, but rather all values that are the same? -- Barry Guidry "Duane Hookom" wrote: I think you need to provide some context and sample data as well as desired results. Sum and Max work against a group of records while "another field is null" seems to work against just a single record. -- Duane Hookom Microsoft Access MVP "Barry" wrote: I would like to make a query on a table on one field to 'sum' or 'max' the field based on 'if' another field is null or not. Any idea on how I would go about this? Please be generous as I am not an Access expert :-) -- Barry |
#7
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I am trying a SQL statement such as "SELECT Max(IIf([Qual] Is Not
Null,[Result],0), Sum(IIf([Qual] Is Null,[Result],0)) AS Expr1 FROM xylenes;" to try to combine the two actions (sum or max) but it is returning an error that I have a syntax error, missing operator. I have never queried in SQL View, so any advice as to how I can correct the above type of action would be appreciated. -- Barry Guidry "Duane Hookom" wrote: If I understand correctly, Allen Browne's suggestion should work. It's difficult to determine since you included a data record 4... ...2222 that seems to be ignored and the "4" is the same as the result you are expecting from the Result column. -- Duane Hookom Microsoft Access MVP "Barry" wrote: Yes, Duane you are right...the null field is based on each record, but I would like the statement to sum the values [Result] if there are any rows of null values in the other field [Qual]. Example: 'Result' 'Qual' 'Lab_id' 1 1111 2 J 1111 3 1111 4 2222 ---------------------------- 4 1111 ('Result' being equal to four because the 'Result' "1" and "3" both have 'Qual' as "null" and the same 'Lab_id' as "1111"). The [Lab_id] is the field I want the query to sort the data, and calculation, by. Is there any way to do this without specifying specific values in the statement, but rather all values that are the same? -- Barry Guidry "Duane Hookom" wrote: I think you need to provide some context and sample data as well as desired results. Sum and Max work against a group of records while "another field is null" seems to work against just a single record. -- Duane Hookom Microsoft Access MVP "Barry" wrote: I would like to make a query on a table on one field to 'sum' or 'max' the field based on 'if' another field is null or not. Any idea on how I would go about this? Please be generous as I am not an Access expert :-) -- Barry |
#8
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You might want to use this as a starting point:
SELECT Lab_ID, IIf(IsNull(Max([Qual])),Sum([Result]),Max([Result])) AS Expr1 FROM Xylenes GROUP BY Xylenes.Lab_ID; -- Duane Hookom Microsoft Access MVP "Barry" wrote: I am trying a SQL statement such as "SELECT Max(IIf([Qual] Is Not Null,[Result],0), Sum(IIf([Qual] Is Null,[Result],0)) AS Expr1 FROM xylenes;" to try to combine the two actions (sum or max) but it is returning an error that I have a syntax error, missing operator. I have never queried in SQL View, so any advice as to how I can correct the above type of action would be appreciated. -- Barry Guidry "Duane Hookom" wrote: If I understand correctly, Allen Browne's suggestion should work. It's difficult to determine since you included a data record 4... ...2222 that seems to be ignored and the "4" is the same as the result you are expecting from the Result column. -- Duane Hookom Microsoft Access MVP "Barry" wrote: Yes, Duane you are right...the null field is based on each record, but I would like the statement to sum the values [Result] if there are any rows of null values in the other field [Qual]. Example: 'Result' 'Qual' 'Lab_id' 1 1111 2 J 1111 3 1111 4 2222 ---------------------------- 4 1111 ('Result' being equal to four because the 'Result' "1" and "3" both have 'Qual' as "null" and the same 'Lab_id' as "1111"). The [Lab_id] is the field I want the query to sort the data, and calculation, by. Is there any way to do this without specifying specific values in the statement, but rather all values that are the same? -- Barry Guidry "Duane Hookom" wrote: I think you need to provide some context and sample data as well as desired results. Sum and Max work against a group of records while "another field is null" seems to work against just a single record. -- Duane Hookom Microsoft Access MVP "Barry" wrote: I would like to make a query on a table on one field to 'sum' or 'max' the field based on 'if' another field is null or not. Any idea on how I would go about this? Please be generous as I am not an Access expert :-) -- Barry |
#9
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I believe that the problem may be that access may try to evaluate both the
true and the false options before deciding which one is wanted. "Barry" wrote in message ... Yes, thanks to Allen Browne, his suggestion, IIf([CreditDate] Is Not Null, [CreditAmount], 0) You can then Sum or choose the Max of this value in the Total row, does work to do one or the other (either sum or max). But, what I am trying to do is to do a combination of the two (both sum or max) in one expression, based on whether or not the other field contains a null value or not. -- Barry Guidry "Duane Hookom" wrote: If I understand correctly, Allen Browne's suggestion should work. It's difficult to determine since you included a data record 4... ...2222 that seems to be ignored and the "4" is the same as the result you are expecting from the Result column. -- Duane Hookom Microsoft Access MVP "Barry" wrote: Yes, Duane you are right...the null field is based on each record, but I would like the statement to sum the values [Result] if there are any rows of null values in the other field [Qual]. Example: 'Result' 'Qual' 'Lab_id' 1 1111 2 J 1111 3 1111 4 2222 ---------------------------- 4 1111 ('Result' being equal to four because the 'Result' "1" and "3" both have 'Qual' as "null" and the same 'Lab_id' as "1111"). The [Lab_id] is the field I want the query to sort the data, and calculation, by. Is there any way to do this without specifying specific values in the statement, but rather all values that are the same? -- Barry Guidry "Duane Hookom" wrote: I think you need to provide some context and sample data as well as desired results. Sum and Max work against a group of records while "another field is null" seems to work against just a single record. -- Duane Hookom Microsoft Access MVP "Barry" wrote: I would like to make a query on a table on one field to 'sum' or 'max' the field based on 'if' another field is null or not. Any idea on how I would go about this? Please be generous as I am not an Access expert :-) -- Barry |
#10
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Duane, that returned one value of "2800" from one group of [Lab_id] in which
[Qual] was a null value. This is a start but the idea was to have it sum both values of the [Lab_id] group "711723" which would have been "2800" + "1900"="4700". You know, as I pondered over my given situation some more, I have come to believe that this will be impossible in Access due to the simple fact that when we usually perform this operation in Excel we must make an intelligent decision as to a priority of summing the [Result] values if there is any null value in [Qual] within the [Lab_id] group, rather than taking the max of the [Result] if all [Qual] values in a [Lab_id] group are not null. You see, I do not see if it will even be possible to set a priority such as this in Access (to first search [Qual] for a null value and sum rather than max the [Result]). This is an example of the test data: NAME DATE LAB_ID ANALYTE RESULT QUAL RW-6 2/24/2006 711721 o-Xylene 0.4 ND RW-5 2/24/2006 711722 o-Xylene 0.4 ND RW-1 2/24/2006 711723 m+p-Xylene 2800 RW-1 2/24/2006 711723 o-Xylene 1900 Duplicate 2/24/2006 711724 m+p-Xylene 2500 Duplicate 2/24/2006 711724 o-Xylene 1700 -- Barry Guidry "Duane Hookom" wrote: You might want to use this as a starting point: SELECT Lab_ID, IIf(IsNull(Max([Qual])),Sum([Result]),Max([Result])) AS Expr1 FROM Xylenes GROUP BY Xylenes.Lab_ID; -- Duane Hookom Microsoft Access MVP "Barry" wrote: I am trying a SQL statement such as "SELECT Max(IIf([Qual] Is Not Null,[Result],0), Sum(IIf([Qual] Is Null,[Result],0)) AS Expr1 FROM xylenes;" to try to combine the two actions (sum or max) but it is returning an error that I have a syntax error, missing operator. I have never queried in SQL View, so any advice as to how I can correct the above type of action would be appreciated. -- Barry Guidry "Duane Hookom" wrote: If I understand correctly, Allen Browne's suggestion should work. It's difficult to determine since you included a data record 4... ...2222 that seems to be ignored and the "4" is the same as the result you are expecting from the Result column. -- Duane Hookom Microsoft Access MVP "Barry" wrote: Yes, Duane you are right...the null field is based on each record, but I would like the statement to sum the values [Result] if there are any rows of null values in the other field [Qual]. Example: 'Result' 'Qual' 'Lab_id' 1 1111 2 J 1111 3 1111 4 2222 ---------------------------- 4 1111 ('Result' being equal to four because the 'Result' "1" and "3" both have 'Qual' as "null" and the same 'Lab_id' as "1111"). The [Lab_id] is the field I want the query to sort the data, and calculation, by. Is there any way to do this without specifying specific values in the statement, but rather all values that are the same? -- Barry Guidry "Duane Hookom" wrote: I think you need to provide some context and sample data as well as desired results. Sum and Max work against a group of records while "another field is null" seems to work against just a single record. -- Duane Hookom Microsoft Access MVP "Barry" wrote: I would like to make a query on a table on one field to 'sum' or 'max' the field based on 'if' another field is null or not. Any idea on how I would go about this? Please be generous as I am not an Access expert :-) -- Barry |
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