How can DUAL() function be used for automatic sorting?

[#1]

I came across a question or a concept where they've used DUAL() for automatic sorting. When a particular column header is double-clicked the data in that field ought to be sorted depending on another field's values.

I was thinking that for sorting (automatic or of any other kind) we would be using something like a SORT() or RANK() function in qlikview.

It didn't make sense to use DUAL() for this purpose.

Can somebody please explain in what kind of scenarios DUAL() is used for sorting purposes??

[marcus_sommer · Accepted solution]

Have a look here:

How to use- Dual()

Dual & Exists – Useful Functions

- Marcus

[Anonymous]

dual() is used like this:

If(Age>20 and Age<=50, Dual('20-50',2),

If(Age>10 and Age<=20, Dual('10-20',1)......

and so on....now with dual() you can sort this age group

[#4]

The links you've posted are pretty helpful and clearly explains with an example what DUAL() does, especially the second link.

Thank you,

krishna kanth