1 use StudentManageDB 2 go 3 --创建主键约束 4 5 if exists(select * from sysobjects where name=‘pk_StudentId‘) 6 alter table Students drop constraint pk_StudentId 7 alter table Students add constraint pk_StudentId primary key(StudentId) 8 9 --创建唯一约束 10 if exists(select * from sysobjects where name=‘uq_StudentIdNo‘) 11 alter table Students drop constraint uq_StudentIdNo 12 alter table Students add constraint uq_StudentIdNo unique(StudentIdNo) 13 14 --创建检查约束 15 if exists(select * from sysobjects where name=‘ck_Age‘) 16 alter table Students drop constraint ck_Age 17 alter table Students add constraint ck_Age check(Age between 18 and 25) 18 19 if exists(select * from sysobjects where name=‘ck_PhoneNumber‘) 20 alter table Students drop constraint ck_PhoneNumber 21 alter table Students add constraint ck_PhoneNumber check(len(PhoneNumber)=11) 22 23 24 update Students set PhoneNumber=‘13099012876‘ where StudentId=10000 25 select * from Students 26 27 --创建默认值 28 if exists(select * from sysobjects where name=‘df_StudentAddress‘) 29 alter table Students drop constraint df_StudentAddress 30 alter table Students add constraint df_StudentAddress default(‘地址不详‘) for StudentAddress 31 32 insert into Students (StudentName,Gender,Birthday,Age,StudentIdNo,PhoneNumber,33 StudentAddress,ClassId) 34 values(‘李小璐‘,‘女‘,‘1989-01-12‘,24,120229198901121315,‘13099012876‘,default,1) 35 36 insert into Students (StudentName,37 ClassId) 38 values(‘李小璐‘,120229198901121316,1) 39 40 --外键约束 41 insert into StudentClass (ClassId,ClassName) values(1,‘软件1班‘) 42 if exists(select * from sysobjects where name=‘fk_ClassId‘) 43 alter table Students drop constraint fk_ClassId 44 alter table Students add constraint fk_ClassId foreign key (ClassId) references StudentClass(ClassId) 45 46 select * from studentClass
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