How to insert a value into a table in a varchchar field, depending on whether it exists in another table?

Question

PHP

Hey! I enter into the user base. There is a roles table. When entering, I want mysql to check if there is such a role in the table with roles, if there is, INSERT occurs. Such a certain range.

Answer 1

in the framework of tsql, this is usually implemented either by logic:
if exists (....) begin
insert
end
or insert from select, where the presence check appears in the select selection condition in one form or another