CHECK

-- 컬럼 레벨 CHECK 제약조건 CREATE TABLE employees ( id INT, age INT CHECK (age >= 20), salary DECIMAL(10,2) CHECK (salary > 0) ); -- 테이블 레벨 CHECK 제약조건 CREATE TABLE products ( id INT, price DECIMAL(10,2), discount DECIMAL(10,2), CONSTRAINT check_price CHECK (price > discount) );

-- CHECK 제약조건 추가 ALTER TABLE employees ADD CONSTRAINT check_age CHECK (age >= 20); -- CHECK 제약조건 비활성화 ALTER TABLE employees NOCHECK CONSTRAINT check_age;

-- CHECK 제약조건 삭제 ALTER TABLE employees DROP CONSTRAINT check_age;