INNER join 等价于 join你可以理解为 join 是 INNER JOIN 的缩写。left JOIN 等价于 left OUTER JOINright JOIN 等价于 RIGHT OUTER JOIN===http://zhidao.baidu.com/link?url=0GN239DZY8SCTEibvjel2iUjnZtm00tRWOenK58mEH8hqPuyMOOlE1gXxcGcAWs9oUxX9q7M9R12P-HamD0nca