How to get a conditional sum()?

[#1]

I have a table that looks like:

Category	MyFlag	Amt
A	y	20.00
A	y	25.60
B	n	30.32
C	n	70.00
C	y	9.10

I want a measure that computes the sum of the selected records where MyFlag='y'.  E.g. if all five are selected the measure is 20+25.6+9.10.  The expression I am using is Sum({$<MyFlag='y'>}Amt), but it always shows 0 (zero). Any ideas for what I'm doing wrong?  The expression editor doesn't show any syntax errors.

Thanks

[oknotsen · Accepted solution]

The correct Set Analysis statement should be this:

sum({$ < MyFlag = {'y'} > } Amt)

Notice the missing curly brackets in your statement .

[Chanty4u]

try this

=Sum( {<MyFlag ={'y'} >} Amt)

[sunny_talwar]

You mentioned about selection, if the sum needs to change based on selection, then I would try this:

=Sum({<Flag *= {'y'}>}Amt)

[#5]

Thanks, but that didn't make any difference.

[#6]

I had actually tried that earlier and it didn't work.  When I tried it again didn't work initially.  However, when I X'ed out my existing selections, then it worked. 

[sunny_talwar]

Well this expression will give you 0 if you select Flag = n, whereas the one provided by others will continue to show you y rows even if you select Flag = n

Not sure if you want this or not

[#8]

Good to know.  I'm sure it will come in handy.  Thanks.

[sunny_talwar]