Question

I have in database:

User:
id | name
1  | one
2  | two
3  | three
4  | four
5  | five


House:
id | name
1  | London
2  | Barcelona

UserHouse:
id_user | id_house
 1      |  1
 2      |  2
 4      |  1

How can i use in SQL query IF and ISSET?

SELECT * from User

I would like receive:

users:

name | has_house
1    | yes
2    | yes
3    | no
4    | yes
5    | no 

I must start my query with SELECT * from User. I can’t star from House or UserHouse.
Is possible? If yes, how?

I can use also DOCTRINE and Symfony.

Answer 1

Try using LEFT JOIN

SELECT  a.id, IF(COALESCE(b.id_user, 1) = 1, 'no', 'yes') has_house
FROM    user a
        LEFT JOIN userhouse b
            on a.id = b.id_user