？求一sql语句：删除a表中满足条件X而且存在于表b中的记录？解决办法

？？？？？求一sql语句：删除a表中满足条件X而且存在于表b中的记录？？？？？
(a,b两表表结构一样，关联条件是Y)
大致是下面的意思：
delete   a   where   X
and   exists(select   *   from   a,b   where   Y)
求助？？？！！！

------解决方案--------------------
delete a from a where X
and exists(select * from b where b.col1?a.col)

------解决方案--------------------

Delete A From A
Where X
And Exists(Select * From B Where Y)
------解决方案--------------------
delete a
from a inner join b on Y
where x