Singular filter on some column works, for example:
SQLQuery.Filter := 'ColumnName="some_filtered_text"'; // OK
But how to apply filter to many columns?
For example this doesn't work:
SQLQuery.Filter := 'ColumnName1="some_filtered_text1",
ColumnName2="some_filtered_text2"'; // Exception
It raises exception: "TApplication.HandleException Operator/function missing".