Retrieve data from table A that does not match the data in table B?

Question

PHP

Hello everyone, can you help?

I have two tables, table A and B.
Table A stores the names of songs in the shortcode field.
Table B contains the name of the song in the musicname field and the id of the song from table A in the id_task field, as well as the user id in the id_user field.

Question: How can I display data from table A that does not match the data in table B. That is:

A.id != B.id_task AND B.id_user != $id_user

Answer 1

It's decided.

SELECT *

FROM A

WHERE NOT EXISTS (SELECT * FROM B WHERE A.id = B.id_task)

Answer 2

SELECT A.* FROM A JOIN B ON ... WHERE ...