合并语句删除 [英] Merge statement delete

问题描述

我有两个表Table_Target（Id int）

I’ve two tables Table_Target(Id int)

Table_Child（childid int，Parent_Id int） - >这里Parent_Id引用Table_Target的Id。

Table_Child(childid int, Parent_Id int) -> here Parent_Id references Id of Table_Target.

使用（holdlock）作为目标合并到table_target中

Merge into table_target with (holdlock) as target

使用table_sourw作为源

Using table_sourw as source

在source.id = target.id

On source.id = target.id

匹配时

更新要更新的语句目标列

Update statement to update target columns

当目标不匹配时

插入要插入源表的语句

如果未与来源匹配则

               
删除

我知道删除会删除Table_Target中的行，但Table_Child中有一行引用了正在删除的ID。我试图从Table_Child写删除子行，但语法不支持它。有没有办法在Merge语句中删除父行之前处理删除子行
？

I know delete would delete the row from Table_Target but there is a row in Table_Child referencing the Id that is being deleted. I tried to write delete child row from Table_Child but syntax doesn’t support it. Is there a way to handle deleting child rows before deleting parent row in Merge statement?

TIA

推荐答案

首先，根据以下查询从Table_Child中删除行：

First, Delete the rows from Table_Child based on the following query:

DELETE FROM Table_Child WHERE Parent_Id IN （

DELETE FROM Table_Child WHERE Parent_Id IN (

   SELECT Id FROM Table_Target WHERE Id Not IN（SELECT Id FROM Table_Source）

   SELECT Id FROM Table_Target WHERE Id NOT IN (SELECT Id FROM Table_Source)

）;

然后执行Merge语句。

And then execute Merge statement.

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