CREATE TABLE people (
person_id INT,
person_name VARCHAR(10),
age TINYINT,
birthday DATE
);
-- 테이블명 변경
ALTER TABLE people RENAME TO friends,
-- 컬럼 자료형 변경
CHANGE COLUMN person_id person_id TINYINT,
-- 컬럼명 변경
CHANGE COLUMN person_name person_nickname VARCHAR(10),
-- 컬럼 삭제
DROP COLUMN birthday,
-- 컬럼 추가
ADD COLUMN is_married TINYINT AFTER age;
DROP TABLE friends;
INSERT INTO people
(person_id, person_name, age, birthday)
VALUES (1, '홍길동', 21, '2000-01-31');
-- 모든 컬럼에 값 넣을 때는 컬럼명들 생략 가능
INSERT INTO people
VALUES (2, '전우치', 18, '2003-05-12');
-- 일부 컬럼에만 값 넣기 가능 (NOT NULL은 생략 불가)
INSERT INTO people
(person_id, person_name, birthday)
VALUES (3, '임꺽정', '1995-11-04');
-- 자료형에 맞지 않는 값은 오류 발생
INSERT INTO people
(person_id, person_name, age, birthday)
VALUES (1, '임꺽정', '스물여섯', '1995-11-04');
-- 여러 행을 한 번에 입력 가능
INSERT INTO people
(person_id, person_name, age, birthday)
VALUES
(4, '존 스미스', 30, '1991-03-01'),
(5, '루피 D. 몽키', 15, '2006-12-07'),
(6, '황비홍', 24, '1997-10-30');
CREATE TABLE people (
person_id INT AUTO_INCREMENT PRIMARY KEY,
person_name VARCHAR(10) NOT NULL,
nickname VARCHAR(10) UNIQUE NOT NULL,
age TINYINT UNSIGNED,
is_married TINYINT DEFAULT 0
);
INSERT INTO people
(person_name, nickname, age)
VALUES ('김철수', '아이언워터', 10);
INSERT INTO people
(person_name, nickname, age)
VALUES ('이불가', '임파서블', -2);
INSERT INTO people
(person_name, nickname, age, is_married)
VALUES ('박쇳물', '아이언워터', NULL, 1);
-- nickname에 NULL, '아이언수' 넣어보기