Выборка из двух таблиц

            $sql = "SELECT * 
                FROM photo
                WHERE photo = '$photo'";
            $query = mysqli_query($connect, $sql) or die(mysqli_error());
            $row = mysqli_fetch_assoc($query);

            $sql = "SELECT * 
                FROM like
                WHERE subject = '$photo'";
            $query = mysqli_query($connect, $sql) or die(mysqli_error());
            $row = mysqli_fetch_assoc($query);

            $sql = "SELECT * 
                FROM photo
                WHERE photo = '$photo'
                UNION
                SELECT * 
                FROM like
                WHERE subject = '$photo'";

Warning: mysqli_error() expects exactly 1 parameter, 0 given in /var/www/vh131297/data/www/danfa.org/index.php on line 25

        if (file_exists(ORIGINAL . $photo))
        {
            $sql = "SELECT * 
                FROM photo
                WHERE photo = '$photo'";
            $query = mysqli_query($connect, $sql) or die(mysqli_error());
            $row = mysqli_fetch_assoc($query);
            
            $title = $lang['view_photo'] . ': ' . $row['photo_title'];

            $query = mysqli_query($connect, $sql) or die(mysqli_error());

"SELECT p.*, l.*
 FROM photo p, like l
 WHERE p.photo = '$photo'
 AND l.subject = p.photo"

            $sql2 = "SELECT SUM(plus), SUM(minus)
                FROM likes 
                WHERE subject = '$photo'";
            $query2 = mysqli_query($connect, $sql2) or die(mysqli_error());
            $row2 = mysqli_fetch_assoc($query2);

<?=$row2['minus']?>