Using boolean value in QGIS style rule

Question

I'm trying to make a style based on rules, and I want to use a boolean field I have created for that.

But I do the following:

"field" like 'TRUE'
"field" like TRUE
"field" like 1
"field" like '1'

and nothing is selected.

How can I select true values in a boolean field then? I'm using QGIS reading from PostGIS database.

Answer 1

When using a boolean, you need to use the IS operator instead of LIKE. So your expression should be:

"field" is true

However, since you want to select the fields which are TRUE, you can also shorthen this and use this expression:

"field"

This works because in QGIS the fields will be selected, where the used expression returns TRUE. So on a booleanfield it is enough when the content is TRUE and therefore returning TRUE when evaluating it.

Proof:

Answer 2

I would recommend, in order to see how QGIS views the values, to use the "all unique" button.

You should get a list of values.

Answer 3

Finally I have found the solution:

"field" like 't'