Restrict only '1' and '0' value in sql - sql

Question

I'm currently working in Oracle SQL and I am trying to constrain the integer datatype to only take the values 0 and 1 (for an active item or not).
This is what I currently have:
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);
When I enter this command and run the Select * from ACTIVE_EX line, the value 2 will still be entered into the table with no error.

Answer 1

How about this?
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>
As you can see, decimal values between 0 and 1 can be entered, but will be rounded so the final result will still be 0 or 1.