一个多表嵌套查询的sql语句

select batch_no "批次号",get_id "分类" from (
select(
select plan1.batch_no from product_plan plan1 where plan1.item_no=(select head1.product_code from wo_head head1 where head1.order_no =bbb)) batch_no, 
(select decode(get_id,'BUY','外购件','MAK','自制件','MB','未定') from item where item_no= aaa) get_id
 from (select req.item_no aaa,req.order_no bbb from process_req req where req.status_id='C'and req.order_no in(select head.order_no  from wo_head head where head.batch_no in (select batch_no from product_plan) or head.product_code in ( select item_no from product_plan )))) order by qty desc