I have a user table and user_friend table. user_friend shows who I am friend with (so it's uid and fid). I want to get the info of all my friends, so I did:
SELECT UID, Name FROM user WHERE UID = (SELECT FID FROM user_friend WHERE UID = 567445724);
but it gives me a Subquery returns more than 1 row, how should I modify this query?
You should try JOIN like
select u.uid,u.name
from user u join user_freinds uf on u.uid=uf.fid
where u.uid=567445724
SELECT UID, Name FROM user
WHERE UID IN (SELECT FID FROM user_friend WHERE UID = 567445724);`
Alternatively, in MySQL, I believe I recall reading that joins are often much fasdter than subselects. So perhaps:
SELECT user.UID, user.Name FROM user, user_friend
WHERE user.UID = user_friend.FID AND user_friend.UID = 567445724;
You have to use the in keyword.
SELECT UID, Name FROM user WHERE UID IN (SELECT FID FROM user_friend WHERE UID = 567445724);
Use IN instead of equals:
SELECT UID, Name FROM user WHERE UID IN (SELECT FID FROM user_friend WHERE UID = 567445724);
select user.uid, user.name from user, user_friends
where user.uid=user_friends.fid
and user.uid=567445724
