How to use the selection result, as in MySQL

Question

I need MySQL code that uses select output in a LIKE statement in WHERE.

I mean something like this:

SELECT id FROM (SELECT id,parent_id FROM units WHERE ptitle 
like '%(SELECT ptitle FROM units WHERE id='".$id."')%')

Answer 1

you need to use concat

SELECT id FROM (

SELECT id,parent_id FROM units WHERE ptitle

like concat('%',(SELECT ptitle FROM units WHERE id='".$id."'), '%')

) sub_table