Join another table with condition

Question

I want to join another table if a column in current table equals to a specific value. ( ENUM type )

for example, assume a status column which has 4 types of ( Public, OnlyMe, Friend, Group )

I want to join table groups only when status = Group

Something like this.

This is not mysql syntax.

SELECT * FROM posts WHERE ( status = Public OR status = OnlyMe OR status = Friend )
OR ( IF(status=Group) JOIN groups )

How can I do that in mysql?

Answer 1

Something like this (I made up several column names for your tables):

SELECT p.id, p.status, p.text, g.name
FROM posts p
    LEFT OUTER JOIN groups g
        ON (p.status = 'Group' AND p.groupId = g.id);