Ignore a field selection but show values for a specific item of that field

[mojtabata]

Assume that we have an application for a company. The fields are [shopName], [month],[year], [sales].

I want to show a chart for trendline of sales of  a specific shop, 'shop1' on month dimension. This can be done by the following set expression: 

sum({<shopName = {shop1}}sales)

 But, when I select another item in my shopName field, this chart shows 'no data to display'. I want this chart to respect my selection in [month] and [year] fields, but disregard any selection made in [shopName] field.
How can I do that?

[edwin · Accepted solution]

The set analysis phrase  (im assuming you did a typo in your post)

sum({<shopName = {'shop1'}>}sales)

 means, ignore/override shopName selection and only choose 'shop1'

so if this is not working, there is some other issue and its not set analysis thats the issue, so dont look at the set analysis, look elsewhere.  also make sure you have the rt syntax as QV is not forgiving when it comes to syntax

providing the QVW might help identify your issue

[mikaelsc · Accepted solution]

also ensure that all your years and months are associated to all your shops... (by adding a record sales = 0 for the years/months where no sales exists for a particular shop ) 

otherwise: you select a year where shop1 doesn't have sales --> you also lose your "shop1 trendline"...