MySQL/PHP計數

Question

我有2個MySQL表，一個用於存儲專輯，另一個用於歌曲。我在表格中顯示了相冊列表，我希望能夠添加名爲songs的列以顯示此相冊中的歌曲數量。現在我有它的方式只是弄亂了我的桌子：

感謝大家的幫助！

Answer 1

假設「播放列表」是什麼，你認爲在播放列表的專輯和第一while循環迭代，我已經重寫你的代碼是這樣的：

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>"; 
}