Question

I have two tables:

1. messages – with following structure

   id
   sender_id
   receiver_id
   message_text

2. users – with following structure

   id
   nickname

I need to join these two tables so I get result like this:

message_id, sender_nickname, receiver_nickname, message_text

sender_id is always set. The problem is I also need messages where receiver_id is 0 so receiver_id can’t be found in user table.

Could someone help me?

Answer 1

select 
m.id,
u1.nickname as sender,
u2.nickname as receiver,
m.message_text
from messages as m
left join users as u1 on u1.id = m.sender_id
left join users as u2 on u2.id = m.receiver_id