mysql - Should I use left join or not in in the following statement?

Question

Implementation: Query records in a that are not related to b {code...} {code...} Which one is better, or if there is another way, please leave an answer.

高洛峰 · Answer

not existsCorrect answer

select id from a where not exists (select 1 from b where a.id=b.aid) and status = 1

習慣沉默 · Answer

I want to use not exists

A brief discussion on the difference between in and not in, exists and not exists in sql