Summarizing control based on unique values different field

[BRC]

I am trying to create a control that sums a field “tstresult” for
unique “eventid” in a query that may contains multiple records with
the same “eventid”. When I use =sum([tstresult]) in the control
source it adds all test results. I can’t do this based strictly on
unique values of “tstresult” because the different “eventid’s” could
have the same “tstresult”. Thanks in advances for any help.

 

[XPS350]

A query to do this could look like:
SELECT eventid, Sum(tstresult) AS SumOfTstresult
FROM YourTable
GROUP BY eventid

Peter
http://access.xps350.com/