It seems that textql doesn't parse the query at all, it imports the CSV into an sqlite3 db and then runs the query against it. What you ask for would be doable

It seems that textql doesn't parse the query at all, it imports the CSV into an sqlite3 db and then runs the query against it. What you ask for would be doable but it would be much more complex (parsing SQL is not that trivial, and people would want to do more complex queries like JOINing multiple CSV files etc., so you can't just look for "from <filename>").