约束(sql 语句)由刀豆文库小编整理，希望给你工作、学习、生活带来方便，猜你可能喜欢“sql语句的check约束”。
use stuinfo
alter table student
add 入学时间 datetime
go
use stuinfo
alter table student
add ID char(20)
use stuinfo
alter table student
add constraint check_1 check(datediff(day,birthday,getdate())>=365*18)use stuinfo
alter table student
add constraint check_2 check(len(ID)=18)
go
use stuinfo
update student
set ID='***321'
where S_number='040102'
use stuinfo
alter table student
add constraint check_3 check(Politics='党员' or Politics='团员' or Politics='群众' or Politics='')
