ALTER TABLE tb ADD CONSTRAINT PK_tb PRIMARY KEY(col1,col2)
Alter table 表名 add constraint 约束名 primary key(字段名)
ALTER TABLE 表名 ADD CONSTRAINT 约束名 PRIMARY KEY(col1,col2)
if object_id('tb') is not null drop table tb go create table tb (name nvarchar(10),age int,sex nvarchar(10),constraint ck primary key (name,sex)) insert into tb select '张三',20,'男' union all select '张三',20,'女' go select * from tb
ADD CONSTRAINT PK_tb PRIMARY KEY(col1,col2)
if object_id('tb') is not null
drop table tb
go
create table tb
(name nvarchar(10),age int,sex nvarchar(10),constraint ck primary key (name,sex))
insert into tb select '张三',20,'男'
union all select '张三',20,'女'
go
select * from tb