alter table(人) 添加ID int主键

这将添加主键和标识种子并填充新列。

试着使用下面的代码:

ALTER TABLE `table name` 
    CHANGE COLUMN `column name` `column name` datatype NOT NULL, 
    ADD PRIMARY KEY (`column name`) ;

alter table(人) 添加ID int主键

这将添加主键和标识种子并填充新列。

删除约束并重新创建它

alter table Persion drop CONSTRAINT <constraint_name>

alter table Persion add primary key (persionId,Pname,PMID)

编辑:

你可以通过下面的查询找到约束名:

select OBJECT_NAME(OBJECT_ID) AS NameofConstraint
FROM sys.objects
where OBJECT_NAME(parent_object_id)='Persion'
and type_desc LIKE '%CONSTRAINT'

我觉得这样应该有用

-- drop current primary key constraint
ALTER TABLE dbo.persion 
DROP CONSTRAINT PK_persionId;
GO

-- add new auto incremented field
ALTER TABLE dbo.persion 
ADD pmid BIGINT IDENTITY;
GO

-- create new primary key constraint
ALTER TABLE dbo.persion 
ADD CONSTRAINT PK_persionId PRIMARY KEY NONCLUSTERED (pmid, persionId);
GO

请尝尝这个

ALTER TABLE TABLE_NAME DROP INDEX `PRIMARY`, ADD PRIMARY KEY (COLUMN1, COLUMN2,..);