Doubt about one expression with set analysis

[#1]

Hi everybody,

I have to do this.

SUM of "Number"

Concept = 'Concept1'

And 'Installation' has to be emtpy , i mean i don't have to have values in this field.

the two first are this

SUM({<Concept = {'Concept1'} >}Number)

But how i do the last thing?

Am i clear?

Thank you, greetings!

[#2]

Is this?

SUM({$<Instalattion={'*'}-{''}, Concept = {'Concept1'} >}Number

If this is correct. Now i wanna have the same but when Instalattion IS NOT empty

how i do that?

Thanks

[marcus_sommer]

Try something like this:

SUM({<Concept = {'Concept1'}, Instalattion -= {'*'} >} Number)

- Marcus

[reshmakala]

Does your original post mean that installation should be a null value? or you do not want to include it in the expression?

[#5]

The field 'Installation' has to be emtpy , it dont have to have vallues, null.

[#6]

It doesn't work!

[#7]

Without the - i dont have errors

[reshmakala]

Hope this helps   

Set analysis exclude null

[#9]

I didn't understand

what i have to put after the =-?

[#10]

OK the answer is THIS

Sum({$<SET THAT IS NOT NULL -= {""}>}THIS IS THE OPERATION)