Sign in to follow this  
Followers 0

How to do a calculation on an aggregate function in an ExecuteSQL statement


7 posts in this topic

Posted

Hi,

 

I have very limited SQL experience and am trying to do some calculations on a SELECT statement in a local FMP database;

 

When I do:

SELECT COUNT(tab) as t, SUM("amounts") as a

FROM SummaryData

WHERE tab >15 GROUP BY tab

 

Result is:

16, -152

17, 113

18, 255

 

When I add in a calculation:

SELECT COUNT(tab) as t, SUM("amounts") as a, a * t

FROM SummaryData

WHERE tab >15 GROUP BY tab

 

Result is (invalid):

?

 
I have tried various combinations that seem to work on standard SQL systems, but Filemaker errors. Does Filemaker SQL not support calculations?
 
Any ideas or pointers would be greatly appreciated.
 
 

Share this post


Link to post
Share on other sites

Posted

Lets say that Filemakers SQL power is kinda limited. The more you dive in, the more problems you'll encounter. Filemaker is using SQL since Version 10 I think. You have to give them some time :)

Share this post


Link to post
Share on other sites

Posted

Maybe a*t as something? Don't have time to test right now. But I think it is possible.

 

http://filemakerhacks.com/2012/10/19/the-missing-fm-12-executesql-reference/

 

I tried a*t as test, as suggested Fitch, but no luck. Maybe calculations on aggregates just not work with filemaker SQL at this stage, as eluded to by Electric_Soul. 

 

Perhaps I'll have to load up MAMP (does it still exist??) and play with mySQL, etc.

Share this post


Link to post
Share on other sites

Posted

When I think about it.......     your query must not work. On which database did your sucsseslfully try your query, where you referenced the aliases in the select  statement?

 

There is a processing order in sql. And this order evaluates aliases with the select statement. The selection of rows comes before that.

 

A simple query like this should not work either, because the where clause doesn't know w. w is being evaluated wit the select clause, and that one comes after there where clause.

 

select weight as w,FROM garbage
where w > 10
 

Share this post


Link to post
Share on other sites

Posted

It has been my experience that filemaker FQL does not like it when you mix aggregate functions with non aggregate functions. If you have Filemaker Advanced you could write a recursive custom function that processes your SQL array result to arrive at the desired result.

Share this post


Link to post
Share on other sites

Posted

It has been my experience that filemaker FQL does not like it when you mix aggregate functions with non aggregate functions. If you have Filemaker Advanced you could write a recursive custom function that processes your SQL array result to arrive at the desired result.

Instead of a CF you could use the VirtualList technic to do calculations on sql-aggregates.
 
Assuming the table VirtualList is filled with the global variable $$vl and the virtuallist column separator is "||", you could do it like this.
 
Let ( [
 
$$vl = ExecuteSQL ( 
"SELECT COUNT(tab), SUM("amounts") 
FROM SummaryData 
WHERE tab >15 GROUP BY tab"
; "||" ; "" )
 
] ;
 
ExecuteSQL ( 
"SELECT Field01, Field02, NUMVAL(Field01) * NUMVAL(Field02)
FROM VirtualList
WHERE Field01 IS NOT NULL"
; "" ; "" )
 
)
 
the NUMVAL operator is needed, if the virtuallists fields are text fields.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0