Question

我有一个表Order，我希望按clientId删除数据。该表每个客户端有超过2071458条记录。而且这个表有16个表的外键引用。禾当我尝试通过clientid删除记录时，删除reocord需要2-4个小时。那么如何才能更快地提高性能呢？我可以使用子查询，如果是，我如何在此查询中使用。以下是我正在使用的查询。

DECLARE @ORDERID int   
DECLARE DEL_RelDataOFOrdeTab CURSOR FOR  
SELECT ORDERID FROM orde_ WHERE CLIENTID = @ClientID  
 OPEN DEL_RelDataOFOrdeTab  

  FETCH NEXT FROM DEL_RelDataOFOrdeTab  INTO @ORDERID  
   WHILE @@FETCH_STATUS = 0  

     BEGIN   
       DELETE FROM AUTHORIZED WHERE ORDERID = @ORDERID  
       DELETE FROM AUTODISPALERTS WHERE ORDERID = @ORDERID  
       DELETE FROM DRIVER_REIMBURSEMENT WHERE ORDERID = @ORDERID  
       DELETE FROM FAXPOD WHERE ORDERID = @ORDERID  
       DELETE FROM GENERICFIELDS WHERE ORDERID = @ORDERID  
       DELETE FROM [Messages] WHERE ORDERID = @ORDERID  
       DELETE FROM ORDAUDIT WHERE ORDERID = @ORDERID  
       DELETE FROM OrderNotification WHERE ORDERID = @ORDERID  
       DELETE FROM OrderNotificationActions WHERE ORDERID = @ORDERID  
       DELETE FROM ORDERSPAID WHERE ORDERID = @ORDERID  
       DELETE FROM ROUTESERVERORDERS WHERE ORDERID = @ORDERID  
       DELETE FROM UnfinalizedOrders WHERE ORDERID = @ORDERID  
       print 'DELETING FROM ORDE_'  
       DELETE FROM orde_ where ORDERID = @ORDERID  
       PRINT @ORDERID  
     FETCH NEXT FROM DEL_RelDataOFOrdeTab INTO @ORDERID  
     END  

CLOSE DEL_RelDataOFOrdeTab   
DEALLOCATE DEL_RelDataOFOrdeTab  

DELETE FROM orde_ WHERE CLIENTID = @ClientID

Answer 1

您可以移除CURSOR，只需使用SUBQUERY。

DELETE FROM AUTHORIZED WHERE ORDERID IN (SELECT ORDERID FROM orde_ WHERE CLIENTID = @ClientID)
DELETE FROM AUTODISPALERTS WHERE ORDERID IN (SELECT ORDERID FROM orde_ WHERE CLIENTID = @ClientID)
DELETE FROM DRIVER_REIMBURSEMENT WHERE ORDERID IN (SELECT ORDERID FROM orde_ WHERE CLIENTID = @ClientID)
DELETE FROM FAXPOD WHERE ORDERID IN (SELECT ORDERID FROM orde_ WHERE CLIENTID = @ClientID)
DELETE FROM GENERICFIELDS WHERE ORDERID IN (SELECT ORDERID FROM orde_ WHERE CLIENTID = @ClientID)
DELETE FROM [Messages] WHERE ORDERID IN (SELECT ORDERID FROM orde_ WHERE CLIENTID = @ClientID)
DELETE FROM ORDAUDIT WHERE ORDERID IN (SELECT ORDERID FROM orde_ WHERE CLIENTID = @ClientID)
DELETE FROM OrderNotification WHERE ORDERID IN (SELECT ORDERID FROM orde_ WHERE CLIENTID = @ClientID)
DELETE FROM OrderNotificationActions WHERE ORDERID IN (SELECT ORDERID FROM orde_ WHERE CLIENTID = @ClientID)
DELETE FROM ORDERSPAID WHERE ORDERID IN (SELECT ORDERID FROM orde_ WHERE CLIENTID = @ClientID)
DELETE FROM ROUTESERVERORDERS WHERE ORDERID IN (SELECT ORDERID FROM orde_ WHERE CLIENTID = @ClientID)
DELETE FROM UnfinalizedOrders WHERE ORDERID IN (SELECT ORDERID FROM orde_ WHERE CLIENTID = @ClientID)
DELETE FROM orde_ WHERE ORDERID IN (SELECT ORDERID FROM orde_ WHERE CLIENTID = @ClientID)

基本上，它取代了

中的WHERE子句

WHERE ORDERID = @ORDERID

到

WHERE ORDERID IN (SELECT ORDERID FROM orde_ WHERE CLIENTID = @ClientID)

如何提高查询性能以更快地删除子表记录

1 个答案: