Question

I need to run the following query (this is a simplification of my process):

SELECT * 
FROM (SHOW COLUMNS FROM T1)

It errors out.

Answer 1

This is what you want to do:

select * from (
    select * from INFORMATION_SCHEMA.COLUMNS 
    where table_name = 'T1'
) dt

You cannot use SHOW COLUMNS in a subquery, but by using the INFORMATION_SCHEMA.COLUMNS table, you have much more information available, not only the column name, for instance.