Question

There are two tables

Table A
id column_a
01 abc
01 abc
02 abc
02 abc
02 abc
03 abc
03 abc
04 abc

Table B

id column_b
01 abc
02 abc
02 abc
03 abc
04 abc

I’d like to compare those two tables above and to get the results in table a but not in table b like:

id column_a
01 abc
01 abc
02 abc
03 abc

How could i do it in MySQL?

Thanks a lot!

Updated

Answer 1

SELECT A.* FROM A
LEFT JOIN B ON A.column_a = B.column_b AND A.id = B.id
WHERE B.id IS NULL