sql中为表加约束的sql语句

sql中为表加约束的sql语句收藏 --为表userinfo的loginName列加唯一约束

alter table userinfo

add constraint UQ_loginName unique(loginName)

--为表userinfo的loginName列加主键约束

alter table userinfo

add constraint PK_loginName primary key(loginName)

--为表userinfo的age列添加检查约束

alter table userinfo

add constraint CK_age check(age between 0 and 100)

--为表userinfo的address列添加默认约束

alter table userinfo

add constraint DF_address default('地址不详') for address

--为表userinfo的classId添加对应classinfo表的classId主键的外键

alter table userinfo

add constraint PK_classId foreign key(classId) references classinfo(classId)

--创建聚集索引

create clustered index Idx_Area_ID on Company(Area_ID)

--创建唯一聚集索引

create unique clustered index Idx_Un_Area_ID on Company(Area_ID)

--创建非聚集索引

create nonclustered index Idx_Area_ID on Company(Area_ID)

--删除约束

if exists(select * from sys.default_constraints where name='DF_address' and parent_object_id=object_id('userinfo'))

begin

alter table userinfo drop constraint DF_address

end