1、打开plsql客户端,登录oracle数据库;
2、编写sql,创建测试表test_constraint,并添加约束条件sex只能为0或1;
create table test_constraint (
id int,
sex char(2),
constraint Check_sex check (sex ='0' or sex ='1'));
3、插入测试数据,可以发现sex为0或1的数据,可以正常插入;
insert into test_constraint values(1001, 0);
insert into test_constraint values(1002, 0);
insert into test_constraint values(1003, 1);
commit;
4、另插入测试数据,sex为2,可以发现程序会报错;
insert into test_constraint values(1004, 2);
创建表结构(约束):
create table table_name (
id int,
sex char(2),
constraint Check_sex check (sex ='0' or sex ='1'))
)
修改(约束)
alter table table_name
add constrainst cons_name check (sex = '0' or sex = '1')
你是想这个字段只能录入0或1吗?