小编pro*_*lin的帖子

<?php
$db = new mysqli(//editted out db credentials);

if($db->connect_errno > 0){
    die('Unable to connect to database [' . $db->connect_error . ']');
}
$sql = "SELECT m.ID, m.Title, GROUP_CONCAT(a.Title) AS Artist
FROM mp3s m
LEFT JOIN artist_relations ar ON ar.mp3ID = m.ID
LEFT JOIN artists a ON a.ID = ar.artistID
GROUP BY m.ID
ORDER BY ID
LIMIT 0,30;
";

if($result = $db->query($sql)){
echo "<table>";
while($row = $result->fetch_assoc()){
    echo "<tr>";  
    echo "<td>".$row['Title']."</td>";
    echo "<td>".$row['Artist']."</td>";
    echo "</tr>";  
}
echo "</table>";
}

?> 

该查询正常工作，但是速度非常慢。 …