MySQL/PHP计数

Question

我有2个MySQL表，一个用于存储专辑，另一个用于歌曲。我在表格中显示了相册列表，我希望能够添加名为songs的列以显示此相册中的歌曲数量。现在我有它的方式只是弄乱了我的桌子：

感谢大家的帮助！

Answer 1

假设“播放列表”是什么，你认为在播放列表的专辑和第一while循环迭代，我已经重写你的代码是这样的：

while($row = mysql_fetch_array($rs)) { 
    echo "<tr>\n"; 
    echo "<td>".$row['playlist_id']."</td>"; 

    // Assuming playlist_id is an integer value in your database 
    $query = " 
     SELECT Playlist_id, COUNT(Playlist_id) AS songCount 
     FROM ws_music 
     WHERE Playlist_id = ". intval ($row['playlist_id']) ." 
     GROUP BY Playlist_id 
    "; 
    $result = mysql_query($query) or die(mysql_error()); 
    // No need for the second while loop 
    $row2 = mysql_fetch_array($result); 
    echo "<td>There are ". $row2['songCount'] ." ". $row2['Playlist_id'] ." song.</td>"; 
    echo "</tr>"; 
}