SQL Server约束取值范围

CHECK约束

create table student(
Sno int not null primary key,
age int check(age between 1 and 100)
sex char(2) check(sex in('男bai','女du')
DempNo int)

修改取值范围：https://blog.csdn.net/qq_27494201/article/details/102507259

撤销 CHECK 约束

https://zhidao.baidu.com/question/2052026833620410067.html

添加CHECK约束：https://blog.csdn.net/qq_43551373/article/details/87865739

SQL Server中的约束（六种约束）：https://www.cnblogs.com/xiaolinshushu/p/3256110.html