将主键添加到现有表 [英] Add primary key to existing table
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问题描述
我有一个名为 Persion
的表。在此表中,我有5列:
I have an existing table called Persion
. In this table I have 5 columns:
- persionId
- Pname
- PMid
- 描述
- Pamt
- persionId
- Pname
- PMid
- Pdescription
- Pamt
创建此表时,我将 PersionId
和 Pname
设置为主键
When I created this table, I set PersionId
and Pname
as the primary key.
我现在想在主键-PMID中再增加一列。如何编写 ALTER
语句来做到这一点? (我的表中已经有1000条记录)
I now want to include one more column in the primary key - PMID. How can I write an ALTER
statement to do this? (I already have 1000 records in the table)
推荐答案
放置约束并重新创建
alter table Persion drop CONSTRAINT <constraint_name>
alter table Persion add primary key (persionId,Pname,PMID)
编辑:
您可以通过以下查询找到约束名称:
you can find the constraint name by using the query below:
select OBJECT_NAME(OBJECT_ID) AS NameofConstraint
FROM sys.objects
where OBJECT_NAME(parent_object_id)='Persion'
and type_desc LIKE '%CONSTRAINT'
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