Using COUNT() with columns that don't use COUNT() when the table is join fails

[Cheyenne Forbes]

 this query fails:

SELECT COUNT(fr.friend_1), u.first_name
>
>         FROM users AS u
>
>         LEFT JOIN friends AS fr ON u.id = fr.friend_2
>
>
with:

SQLException: ERROR 1018 (42Y27): Aggregate may not contain columns not in
> GROUP BY. U.FIRST_NAME
>

TABLES:

users table with these columns ( id, first_name, last_name )


friends table with these columns ( friend_1, friend_2 )