Qlikview - sum in expressions

Question

When I press buton I activate sheet where I have the trigger
onActivate sheet -> Select In Field -> Posting Month -> (JAN|FEB|MAR)

and I need expression to show bar chart with price for month jan,feb,mar I create this expression

if(PostingMonth = 'JAN' ,Sum(Price))
+ if(PostingMonth = 'FEB' ,Sum(Price)) 
+ if(PostingMonth = 'MAR' ,Sum(Price))

but I got No data to displey.

Any idea?

Answer 1

Try sum({<PostingMonth = {'JAN', 'FEB', 'MAR'}>} Price)