Sort by custom expression in QGIS

Question

I would like to sort child records in form view of attributes in QGIS to be sorted by an integer field but in the same time show a different expression in from list. When setup it's working fine - expression displayed by the expression"first_field"||' - '||"second_field", sorted just by the first integer field "first_field"

But when I move to the next parent record it's sorted by the compund expression as a string. The same happens with a simple form view of table without childs when you reopen the table form. The custom sorting expression is still there but not applying. I'm not sure if it's a bug or I'm missing something.

Version Of QGIS 3.22.6

Answer 1

I think it's a bug, the same thing happens to me when closing the form and reopening.

Your best workaround for now may be to use zero-padding for the first field in the display expression (e.g. lpad("first_field",4,'0') || ' - ' || "second_field") resulting in e.g. 0059 - 114, 0867 - 1254, and not using a custom sort expression.

That way it will sort in the correct order. (You might choose to use zero-padding for the second field too just so it looks better).