Drop down variable not working

I’m using SQLite as my data source while creating a drop-down variable. But, I didn’t get any values in the drop-down list and it’s throwing an Error: near “UNION”: syntax error in SQLite. I didn’t use any UNION syntax in my variable query.

Please show us what your variable query is, even if it doesn’t contain an
explicit union.

Antony.

select distinct(column_name) from table_name;