mysql - 需要对两个表编写查询

Question

我有两张 table

Member (member_id,...)
friend-requests(member_id, friend_id)

我需要从成员表中获取member_id为19且不在friend_id列中的所有记录

Answer 1

select * from member join friend-requests
on member.member_id=friend_requests.member_id
where
member.member_id=19
and
not exists (select f.member_id from friend-requests f where f.mmeber_id = member.member_id)