DB- 오라클 OLD JOIN

• 오라클 만의 쿼리, 오라클이 과거에 사용했었던 조인문장에 대해서 알아보겠다.

• ANSI INNER JOIN

  SELECT N.ID , N.TITLE, M.NAME
  FROM
  MEMBER M
  INNER JOIN NOTICE N ON M.ID = N.WRITER_ID
  WHERE M.ID= 'newlec';
  

• Oracle INNER JOIN

  SELECT N.ID, N.TITLE, M.NAME
  FROM MEMBER M, NOTICE N
  WHERE M.ID=N.WRTER_ID AND M.ID = 'newlec';
  

  -> WHERE 절을 사용한다. 보기가 불편하고 깔끔하지못하다.

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• ANSI OUTER JOIN

  SELEC N.*, M.NAME WRITER_NAME
  FROM NOTICE N LEFT OUTER JOIN MEMBER M
  ON M.ID = N.WRITER_ID
  

• Oracle OUTER JOIN

  SELECT N.*, M.NAME WRITER_NAME
  FROM NOTICE N, MEMBER M
  WHERE N.WRITER_ID = M.ID(+)
  

  -> 거꾸로 되있어서 주의해서 써야된다.

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• ANSI CROSS JOIN

  SELECT N.*, M.NAME WRITER_NAME
  FROM MEMBER M CROSS JOIN NOTICE N
  

• Oracle CROSS JOIN

  SELECT N.*, M.NAME WRITER_NAME
  FROM NOTICE N, MEMBER M;