在 UPDATE 触发器中 - 获取不带列名称的主键

发布于 2024-09-25 06:58:07 字数 588 浏览 4 评论 0原文

我需要在不知道主键列名称的情况下更新 DateModified 列。

基本上，我有一个像这样的简单 UPDATE 触发器：

CREATE TRIGGER updated_SCHEMA_TABLE
 ON [SCHEMA].[TABLE]
   AFTER UPDATE AS 
     BEGIN 
       SET NOCOUNT ON; 
       UPDATE [SCHEMA].[TABLE] 
       SET DateModified = getdate() 
       WHERE [PRIMARYKEY]
       IN (SELECT [PRIMARYKEY]
       FROM Inserted)
     END

但不知道主键的列名称，因为触发器将以编程方式生成（请参阅此问题了解原因）。

这可能吗？

原文

I need to update the DateModified Column without knowing the name of the Primary Key Column.

Basically, I've got a plain-jane UPDATE trigger like this:

CREATE TRIGGER updated_SCHEMA_TABLE
 ON [SCHEMA].[TABLE]
   AFTER UPDATE AS 
     BEGIN 
       SET NOCOUNT ON; 
       UPDATE [SCHEMA].[TABLE] 
       SET DateModified = getdate() 
       WHERE [PRIMARYKEY]
       IN (SELECT [PRIMARYKEY]
       FROM Inserted)
     END

but won't know the primary key's column name because the trigger will be generated programmatically (see this question as to why).

Is this possible?

分享到QQ

分享到微博

如果你对这篇内容有疑问，欢迎到本站社区发帖提问参与讨论，获取更多帮助，或者扫码二维码加入 Web 技术交流群。

发布评论

需要登录才能够评论，你可以免费注册一个本站的账号。

一个人的夜不怕黑 2024-10-02 06:58:07

好吧，也许我把这部分作为上一个问题中的“练习”有点不公平。

这适用于具有单列 PK 的表。从这些开始，然后返回并通过复合 PK 手动调整这些可能是最简单的。

select 'create trigger updated_'+s.name + '_' + t.name + ' on  ' + quotename(s.name) + '.' + quotename(t.name) 
       + ' after update as'
       + ' begin '
       + ' set nocount on; '
       + ' update t'
       + '     set [DateModified] = getdate()'
       + '     from inserted i'
       + '         inner join ' + quotename(s.name) + '.' + quotename(t.name) + ' t'
       + '             on i.' + quotename(c2.name) + ' = t.' + quotename(c2.name)
       + ' end'
    from sys.columns c
        inner join sys.tables t
            on c.object_id = t.object_id
        inner join sys.schemas s
            on t.schema_id = s.schema_id
        inner join sys.indexes i
            on t.object_id = i.object_id
        inner join sys.index_columns ic
            on i.object_id = ic.object_id
                and i.index_id = ic.index_id
        inner join sys.columns c2
            on ic.object_id = c2.object_id
                and ic.index_id = c2.column_id
    where c.name = 'DateModified'
        and t.type = 'U'
        and i.is_primary_key = 1

OK, perhaps I was a bit unfair leaving this part as an "exercise" in the previous question.

This would work for tables with a single column PK. It might be easiest to start with these and then go back and manually adjust those with a composite PK.

select 'create trigger updated_'+s.name + '_' + t.name + ' on  ' + quotename(s.name) + '.' + quotename(t.name) 
       + ' after update as'
       + ' begin '
       + ' set nocount on; '
       + ' update t'
       + '     set [DateModified] = getdate()'
       + '     from inserted i'
       + '         inner join ' + quotename(s.name) + '.' + quotename(t.name) + ' t'
       + '             on i.' + quotename(c2.name) + ' = t.' + quotename(c2.name)
       + ' end'
    from sys.columns c
        inner join sys.tables t
            on c.object_id = t.object_id
        inner join sys.schemas s
            on t.schema_id = s.schema_id
        inner join sys.indexes i
            on t.object_id = i.object_id
        inner join sys.index_columns ic
            on i.object_id = ic.object_id
                and i.index_id = ic.index_id
        inner join sys.columns c2
            on ic.object_id = c2.object_id
                and ic.index_id = c2.column_id
    where c.name = 'DateModified'
        and t.type = 'U'
        and i.is_primary_key = 1

回复收藏 0 原文

拥醉 2024-10-02 06:58:07

如果您能够从标识列构建所有主键：

SELECT table_name, column_name
FROM INFORMATION_SCHEMA.COLUMNS
where COLUMNPROPERTY (OBJECT_ID(Table_Name),Column_Name,'IsIdentity') = 1
 and table_schema = [SCHEMA] and table_name = [TABLE]

否则，您将必须使用所有 sys 表来查看索引（干得好，乔）。

If you were able to build all of your primary keys from identity columns:

SELECT table_name, column_name
FROM INFORMATION_SCHEMA.COLUMNS
where COLUMNPROPERTY (OBJECT_ID(Table_Name),Column_Name,'IsIdentity') = 1
 and table_schema = [SCHEMA] and table_name = [TABLE]

otherwise, you will have to look through the indexes using all of the sys tables (good work Joe).

回复收藏 0 原文