Question

通过这篇出色的帖子https://stackoverflow.com/a/9755787/9502397，我现在更好地了解了如何使用Join返回具有不同表中相似引用的结果列表。

运行Select查询后，我将得到结果列表所示的列表

select 
    a.OrderDate,
    c.StaffID,
    c.Activate  
from
    tbl_Order a

join tbl_OrderDetails b
    on a.OrderID = b.OrderID

join tbl_Staff c
    on b.StaffID = c.StaffID

where c.Activate = 'False'

但是，如何使用该结果列表并从tbl_Order中删除这些行？

Answer 1

如有疑问，请使用exists：

delete 
from tbl_order a
where exists 
(
select 1 
from tbl_OrderDetails b
inner join tbl_staff c
on b.StaffID = c.StaffID
and c.Activate = 'False'
where b.Order_id = a.Order_id
)

Answer 2

您还可以使用通用表表达式来分隔对结果集的查询，并删除结果集和所需表中存在的数据：

 WITH cte AS
     (
     select 
    a.OrderDate,
    c.StaffID,
    c.Activate  
from
    tbl_Order a

join tbl_OrderDetails b
    on a.OrderID = b.OrderID

join tbl_Staff c
    on b.StaffID = c.StaffID

where c.Activate = 'False'
     )
     Delete
     FROM cte t1
     INNER JOIN tbl_Order t2
     ON t1.Order_id = t2.Order_id;

Answer 3

您可以使用DELETE FROM WHERE ()IN ()表单，这是代码中的样子：

DELETE FROM
  tbl_Order k
WHERE (k.OrderID) IN (
  SELECT
    a.OrderID 
  FROM
    tbl_Order a
  JOIN tbl_OrderDetails b
    ON a.OrderID = b.OrderID
  JOIN tbl_Staff c
    ON b.StaffID = c.StaffID
  WHERE c.Activate = 'False' )

使用SELECT提取要删除的OrderID时，DELETE的WHERE仅选择具有要删除的ID的行。

Answer 4

您可以在DELETE中使用JOIN，就像使用SELECT一样。只需确保“删除”中的别名来自您要从中删除数据的表即可。

DELETE a 
FROM
    tbl_Order a
INNER JOIN tbl_OrderDetails b
    on a.OrderID = b.OrderID
INNER JOIN tbl_Staff c
    on b.StaffID = c.StaffID
WHERE c.Activate = 'False'

SQL-删除从查询结果中过滤出的行

4 个答案: