Question

我目前正在使用Oracle SQL，并且试图将整数数据类型限制为仅接受值0和1（无论是否为活动项）。

这是我目前拥有的：

    CREATE TABLE ACTIVE_EX (
        ACTIVE int NOT NULL 
           CONSTRAINT check_active_ind CHECK (ACTIVE = 0 OR ACTIVE = 1)
    );

    SELECT * FROM ACTIVE_EX;
    INSERT INTO ACTIVE_EX(ACTIVE)values(2);

当我输入此命令并运行Select * from ACTIVE_EX行时，值2仍将正确输入表中。

Answer 1

怎么样？

SQL> create table test
  2    (active int not null
  3       constraint ch_active check (active in (0, 1))
  4    );

Table created.

SQL>
SQL> insert into test values (-1);
insert into test values (-1)
*
ERROR at line 1:
ORA-02290: check constraint (SCOTT.CH_ACTIVE) violated


SQL> insert into test values (2);
insert into test values (2)
*
ERROR at line 1:
ORA-02290: check constraint (SCOTT.CH_ACTIVE) violated


SQL> insert into test values (100);
insert into test values (100)
*
ERROR at line 1:
ORA-02290: check constraint (SCOTT.CH_ACTIVE) violated


SQL> insert into test values (0.3);

1 row created.

SQL> insert into test values (1.2);

1 row created.

SQL> insert into test values (3.8);
insert into test values (3.8)
*
ERROR at line 1:
ORA-02290: check constraint (SCOTT.CH_ACTIVE) violated


SQL> select * From test;

    ACTIVE
----------
         0
         1

SQL>

如您所见，可以输入0到1之间的十进制值，但是会四舍五入，因此最终结果仍为0或1。

在SQL中仅限制'1'和'0'值

1 个答案: