INNER JOIN

 

 

양쪽 모두에 있는 행만으로 만든 테이블

 

SELECT * FROM topic
INNER JOIN author 
      ON topic.author_id=author.aid

INNER JOIN된 테이블

SELECT * FROM topic
INNER JOIN author
        ON topic.author_id=author.id
INNER JOIN profile.pid=author.profile_id