一个SQL关联查询的问题。求解

回复讨论(解决方案)

select *  from PRO,       (select * from ATTR2pro where attr_id=1 and value=15) t1,        (select * from ATTR2pro where attr_id=2 and value=20) t2  where PRO.pro_id=t1.pro_id and PRO.pro_id=t2.pro_id

楼上正解。感谢