MySQL的使用具有和計數

Question

正在試圖刪除刪除與子查詢的幾個條目使用以下查詢：

首先，我找到這些條目，我想用這個查詢刪除：

SELECT guid FROM account GROUP BY guid,type HAVING count(type) > 1); 

然後我這個查詢添加到DELETE語句：

DELETE FROM account WHERE guid IN (SELECT guid FROM account GROUP BY guid,type HAVING count(type) > 1); 

，但我得到這個錯誤：

您不能指定更新目標表「帳戶」 FROM子句

Answer 1

我認爲你需要使用臨時表以實現您的需求如下：

1. 第一步：創建臨時表

   CREATE TEMPORARY TABLE MyTemp 
   SELECT guid FROM account 
   GROUP BY guid,type HAVING count(type) > 1; 
   

2. 使用臨時表中的delete語句

   DELETE FROM account 
   WHERE guid IN (SELECT guid FROM MyTemp); 
   

3. 刪除臨時表

   DROP TEMPORARY TABLE MyTemp; 
   

編輯：我覺得與* 兩個嵌套選項卡解決萊也可以工作：

DELETE FROM account 
    WHERE guid IN 
    (SELECT guid FROM 
     (SELECT guid FROM account 
     GROUP BY guid,type HAVING count(type) > 1) as MyTemp 
    ) 

Answer 2

首先創建視圖

create view view_acct as 
SELECT guid FROM account 
GROUP BY guid,type HAVING count(type) > 1; 

使用後視圖

DELETE FROM account WHERE guid in (select * from view_acct); 

Answer 3

你的問題就解決了，只是做如下..

DELETE FROM account 

     WHERE guid IN 

    (SELECT * FROM 

     (SELECT guid FROM account 

      GROUP BY guid,type 

      HAVING count(type) > 1) AS a);