Question

What’s the correct syntax to achieve this using 1 query instead of 2?

$result = mysql_query(SELECT * FROM users);

while($row = mysql_fetch_array($result)){
    $result = mysql_query(SELECT SUM(balance) FROM users_account WHERE uid=$row[id]);
}

Answer 1

This will return all records form user_account table with user info :-

    SELECT SUM(ua.balance),u.*,ua.* FROM users_account ua
    left join users u on ua.users_account=u.id
    GROUP BY u.id