SQL中的左连接先内查询

形如：
select a.1,a.2,a.3,b.1,b.2,b.3 from (select * from xxx where xx1=‘tj’) a left join table2 b on a.1=b.1 and b.table22=‘tj2’
例如：
SELECT A.PRD_NO,A.CUS_NO,A.SUP_PRD_NO,b.nouse_dd FROM (SELECT * from prdt_cus1 a where a.cus_no=‘BBB’) A left join prdt b on a.prd_no=b.prd_no AND B.NOUSE_DD IS NOT NULL