oracle語句如何過濾重復信息？

select distinct * from (selectrec.pk_corp as pk_corp ,rec.barcode ,sq.ckxh as ckxh,case when dcb.pk_ql_qdyt_lc_ckpyjj is not null then 0 else dcb.fsgs end as fsnum ,dcb.cksh as sqbillno,dcb.gsnum ,dcb.sygs as synum ,dcb.fsgs as jjnum ,dcb.outbillno ,dcb.outdatefrom ql_qdyt_js_receive recleft join ql_qdyt_lc_cksq sq on rec.barcode=sq.applysamplenumleft join ql_qdyt_dc_qddc dc on sq.applysamplenum=dc.barcodeleft join ql_qdyt_dc_qddc_b dcb on dc.pk_qdyt_dc_qddc=dcb.pk_qdyt_dc_qddcwhere nvl(rec.dr,0)=0and nvl(sq.dr,0)=0and nvl(dc.dr,0)=0and nvl(dcb.dr,0)=0and rec.vbillstatus=1and dc.vbillstatus=1and sq.vbillstatus=1and dcb.pk_qdyt_lc_cksq is not null);