Rookiss Part5 데이터베이스 : INSERT DELETE UPDATE

🙇‍♀️INSERT DELETE UPDATE

🪐INSERT

INSERT

• 연습할 부분 (salaries)

  SELECT *
  FROM salaries
  ORDER BY yearID DESC
  

• INSERT INTO [테이블명] VALUES (값, …)

  INSERT INTO salaries
  VALUES (2022, 'KOR', 'NL', 'presnet', 99999999)
  

• 데이터를 하나 빼먹으면? -> Error

  INSERT INTO salaries
  VALUES (2022, 'KOR', 'NL', 'present2')
  

• INSERT INTO [테이블명] (열, …) VALUES (값, …)

  INSERT INTO salaries(yearID, teamID, playerID, lgID, salary)
  VALUES (2022, 'KOR', 'present2', 'NL', 9999999)
  

• 테이블 설정에 따라 모든 정보를 입력하지 않아도 된다
• salaries는 연봉이 기본 NULL

  INSERT INTO salaries(yearID, teamID, playerID, lgID)
  VALUES (2022, 'KOR', 'present3', 'NL')
  

🪐DELETE vs UPDATE

• DELETE FROM [테이블명] WHERE [조건]
• WHERE를 안붙이면 통채로 사라짐

  DELETE FROM salaries
  WHERE playerID = 'present3'
  

• UPDATE [테이블명] SET [열 = 값, ] WHERE [조건]
• WHERE를 안붙이면 모든 조건에서 실행됨

  UPDATE salaries
  SET salary = salary * 2, yearID = yearID + 1
  WHERE teamID = 'KOR'
  

DELETE FROM salaries
WHERE yearID > 2020

• DELETE vs UPDATE
• 물리적삭제 vs 논리삭제