mysql query two row from two tables

Question

I have this Query to call information form two table.

DB::get("SELECT friends. * , (SELECT `login` FROM `users` WHERE `users`.`id` = friends.`user_id`) AS `login` FROM `friends` WHERE `id_user`='" . $this->user['id'] . "' ORDER BY `id` DESC LIMIT ")

So if user is on friends list show username , i would like to get username and avatar. Avatar row is avatar . I try with this.

DB::get("SELECT friends. * , (SELECT `login`, `*avatar*` FROM `users` WHERE `users`.`id` = friends.`user_id`) AS `login` FROM `friends` WHERE `id_user`='" . $this->user['id'] . "' ORDER BY `id` DESC LIMIT ")

And give me the error

SQLSTATE[21000]: Cardinality violation: 1241 Operand should contain 1 column(s)

where is the mistake?

Answer 1

You need to use JOIN , eg:

SELECT f.*, u.*
FROM friends f JOIN users u ON f.user_id = u.id
WHERE f.id_user = <your_id>
ORDER BY id DESC LIMIT <your_limit>;

Answer 2

First of all you should use Prepared Statement and Second, you can't write inline view, which has two columns

SELECT friends. * , (SELECT `login`, `*avatar*` FROM ..

instead you should use JOIN , which might be efficient than current approach and more readable.