My attribute table (as in the attached screenshot) shows that there is only 1 element and the rest of the 26 items is filtered out.
How can I turn off this filter?
Best Answer
There is the Query Filter which is defined directly on the layer.
It is a global filter. It filters the data at the moment it enters QGIS and therefore applies to everything, including the attribute table.
As shown in my other solution, you can filter directly, without using SQL queries.
If, however, you still want to filter with SQL, proceed as follows:
Create a new field (virtual field if you want it to update dynamically) with Fild calculator and one of the expressions you provided. Call the field condition and use Boolean (true/false) as field type.
Best Answer
There is the Query Filter which is defined directly on the layer. It is a global filter. It filters the data at the moment it enters QGIS and therefore applies to everything, including the attribute table.
https://docs.qgis.org/3.4/en/docs/user_manual/working_with_vector/query_builder.html