Question

可以使用连接查询根据满足条件删除记录吗？

例如，我有一个链接表连接3条记录。我现在的查询删除了这个表中的一个记录，其中一个id不是IN()内爆的Php数组。我已经意识到，如果数组中不存在id，并且它们属于基于另一个表的链接的某个其他表，则查询应仅从该表中删除记录。

Answer 1

对于SQL Server，命令略有不同：

DELETE FROM TableA
FROM TableA LEFT OUTER JOIN TableB ON TableA.Column = TableB.Column 
WHERE TableB.Column IS NULL

不，这不是拼写错误，是的，你做需要“FROM TableA”两次。至少，您需要第二个FROM（第一个是可选的）。以下优点是它适用于SQL Server和MySQL：

DELETE TableA
FROM TableA LEFT OUTER JOIN TableB ON TableA.Column = TableB.Column 
WHERE TableB.Column IS NULL

Answer 2

我喜欢使用EXISTS子句：

DELETE FROM TableA
WHERE
  <<put your array condition here>> 
  AND NOT EXISTS 
  (SELECT 1 FROM TableB Where TableB.ID=TableA.ID)

Answer 3

您可以使用：

DELETE基于加入：

DELETE A      
FROM TableA AS A
  LEFT OUTER JOIN TableB As B ON A.Id = B.TabaleAId 
WHERE B.Column IS NULL

使用子查删除：

DELETE 
FROM TableA AS A
Where
    A.id not in ( Select B.TabaleAId From Tab;eB As B )

或

DELETE FROM TableA
WHERE Not EXISTS 
  (
    SELECT * 
    FROM TableB As B
    Where B.TableAId = TableA.Id
   )

使用表格式删除

With A 
As
    (
        Select TableA.*
        FROM TableA AS A
            LEFT OUTER JOIN TableB As B ON A.Id = B.TabaleAId 
        WHERE B.Column IS NULL
    )
Delete From A

Answer 4

DELETE FROM TableA
LEFT OUTER JOIN TableB
WHERE TableB.Column IS NULL

将删除tableA中没有TableB中相应记录的记录。这就像你追求的那样吗？

Answer 5

DELETE FROM a
  FROM TableA AS a LEFT OUTER JOIN TableB AS b 
  on a.CALENDAR_DATE = b.CALENDAR_DATE AND a.ID = b.ID 
  Where b.ID is null

您可以先使用select语句并验证要删除的记录，然后删除select语句并使用上述查询语法添加Delete FROM tablename。

Answer 6

基于联接删除的最简单方法如下：

1.使用SELECT语句而不是DELETE语句

写入您的查询

  SELECT COLUMNS
    FROM    Table1
            INNER JOIN Table2  ON Table1.YYY = Table2.XXX

2.用SELECT

替换DELETE FROM TABLE列

 DELETE  FROM Table1
    FROM    Table1
            INNER JOIN Table2 ON Table1.YYY = Table2.XXX

请注意，我们需要指定FROM两次，一个用于DELETE部分，一个用于JOIN部分。

Answer 7

delete from TableA
where id in 
(
   select id from TableA
   except select id from TableB
)

这意味着“从tableA中删除表a中的id而不是表b中的id

否则Merge语句可能对您有帮助（匹配/不匹配时删除等） http://technet.microsoft.com/en-us/library/bb510625.aspx

SQL删除基于连接条件

7 个答案: