[얄코] MySQL 3-4. 데이터 변경, 삭제하기

1. DELETE - 주어진 조건의 행 삭제하기

⭐ Preferences > SQL Editor > Safe Updates 항목 체크오프하고 다시 접속

 

DELETE FROM businesses
WHERE status = 'CLS';

 

DELETE 문으로 행 전체 삭제

DELETE FROM businesses;

INSERT INTO businesses (fk_section_id, business_name, status, can_takeout)
VALUES  (3, '화룡각', 'OPN', 1),
        (2, '철구분식', 'OPN', 1),
        (5, '얄코렐라', 'RMD', 1);

 

* TRUNCATE 문으로 테이블 초기화

TRUNCATE businesses;

INSERT INTO businesses (fk_section_id, business_name, status, can_takeout)
VALUES  (3, '화룡각', 'OPN', 1),
        (2, '철구분식', 'OPN', 1),
        (5, '얄코렐라', 'RMD', 1);

 

 

2. UPDATE - 주어진 조건의 행 수정하기

UPDATE menus
SET menu_name = '삼선짜장'
WHERE menu_id = 12;

 

여러 컬럼 수정하기

UPDATE menus
SET 
  menu_name = '열정떡볶이',
  kilocalories = 492.78,
  price = 5000
WHERE 
  fk_business_id = 4
  AND menu_name = '국물떡볶이';

 

컬럼 데이터 활용하여 수정하기

UPDATE menus
SET price = price + 1000
WHERE fk_business_id = 8;

 

UPDATE menus
SET menu_name = CONCAT('전통 ', menu_name)
WHERE fk_business_id IN (
  SELECT business_id 
  FROM sections S
  LEFT JOIN businesses B
    ON S.section_id = B.fk_section_id 
  WHERE section_name = '한식'
);

 

조건문 없이는 모든 행을 변경

UPDATE menus
SET menu_name = '획일화';