多表连接查询I

多表连接查询

交叉连接

内连接

左连接

右连接

限定条件连接

-- SELECT * FROM student
-- SELECT s.*,j.*  FROM student AS s, jiangjin AS j WHERE s.id=j.sid
-- SELECT  s.*,j.money  FROM student AS s JOIN jiangjin AS j ON s.id=j.id
-- SELECT  s.*,j.* FROM student AS s LEFT JOIN jiangjin AS j ON s.id= j.sid
SELECT  s.*,j.* FROM student AS s RIGHT  JOIN jiangjin AS j ON s.id= j.sid