Question

I need to fix following query:

SELECT *
FROM message_treads
LEFT JOIN usernames ON usernames.uid=message_treads.uid_1
LEFT JOIN usernames ON usernames.uid=message_treads.uid_2

I know i should use aliases, but i am not sure on how to do it here. I know how to do it when there is only one left join of one table, but how to to it when there are more than one?

Answer 1

You are correct, you need to use aliases like so:

SELECT *
FROM message_treads
LEFT JOIN usernames uid1 ON uid1.uid=message_treads.uid_1
LEFT JOIN usernames uid2 ON uid2.uid=message_treads.uid_2