what does a -={} in set analysis exactly do ?

[walid_ballout]

I saw in a set analysis expression something like Sum({< Category={'ABC'}, Subcategory-={} >} Amount).

Is this a legal expression in QlikView ?@@, and what does it exactly do because handling of Nulls is done in some other way as I read on different discussions.

[markusjahr]

It means  "not equal to "

[walid_ballout]

Not equal to Null ? specifically right ?

[markusjahr]

not equal to the selected Subcategory

[vinieme12]

There is a difference between -=  and =-

See attached app, make selections in the listbox to see what happens

[walid_ballout]

sure. there is difference between -= and =-.

i tried what you suggested and apparently they are trying to overcome that there are blank cells in the excel sheet that is loaded for that field (subcategory).

[jonathandienst]

-= means exclude.

{} means the empty set

a -= {} means exclude the empty set. In other words, do nothing.

[jonathandienst · Accepted solution]

To exclude blank values use

a -= {''}

[walid_ballout]

Thanks Jonathan. What you are saying is true. a-={''} excludes blanks in all environments.

However and strangely, if the data source is excel, blank values can also be excluded using a-={}

[jonathandienst]

>>However and strangely, if the data source is excel, blank values can also be excluded using a-={}

I agree that is strange and possibly even a bug, so I would not rely on that.