MYSQL列別名上選擇不工作時使用計數

Question

我必須在名稱爲「plays」的兩個連接表上的類似列，我想區分它們，但我得到「未知列'p.plays'在字段列表中「」。我做錯了什麼？

SELECT *, 
      p.plays AS pl, 
      m.plays AS mp, 
      COUNT(p.sid) frequency,  
FROM  music m 
      JOIN plays p 
      ON p.sid = m.sid 
      INNER JOIN users u 
      ON u.uid = m.uid 
      INNER JOIN downloads d 
      ON d.sid = m.sid   
WHERE  p.time > NOW() - INTERVAL 3 DAY 
      AND p.sid != '' 
      AND m.perms != 'c' 
GROUP  BY m.sid 
ORDER  BY frequency DESC 
      LIMIT 50 

圖片。

表：音樂

表：播放

感謝。

Answer 1

根據您在編輯中提供的表格架構。你不要在plays表這就是有Plays列，爲什麼你收到此錯誤嘗試刪除該p.Plays

SELECT *, 

      m.plays AS mp, 
      COUNT(p.sid) frequency,  
FROM  music m 
      JOIN plays p 
      ON p.sid = m.sid 
      INNER JOIN users u 
      ON u.uid = m.uid 
      INNER JOIN downloads d 
      ON d.sid = m.sid   
WHERE  p.time > NOW() - INTERVAL 3 DAY 
      AND p.sid != '' 
      AND m.perms != 'c' 
GROUP  BY m.sid 
ORDER  BY frequency DESC 
      LIMIT 50