select pe.plm_oid,
       rm.plm_m_id,
       pe.plm_createtime,
       pe.plm_newname,
       pe.plm_pdwgdate,
       pe.plm_ppdwgdate,
       pe.plm_pdwgcode,
       pe.plm_ppdwgcode,
       pe.plm_pdtdesign,
       pe.plm_dpdtdesign,
       pe.plm_pdwgname,
       pe.plm_cxsj,
       pe.plm_tzsj,
       f.plm_oid,
       w.plm_completeddate
  from plm_cus_PROJECTECHFILE pe
  left join PLM_PSM_FILE f
    on pe.PLM_OID = f.PLM_ITEMOID, PLM_PSM_ITEMMASTER_REVISION rm,
 PLM_BPMv_WORKITEM w, plm_bpmv_r_group_data_ins i,
 plm_cus_r_XMHXMJSWJ x
 where i.plm_bosubid = 1
   and w.plm_name like '%批准'
   and pe.plm_xmjswjfl = '设计任务书-电气'
   and i.plm_PROCESSoid = w.plm_processinstanceid
   and i.plm_bomoid = rm.plm_m_oid
   and rm.plm_m_lastrevision = rm.plm_r_revision
   and pe.PLM_ITERATION = rm.plm_r_lastiteration
   and rm.plm_r_oid = pe.plm_revisionoid
   and x.plm_rightobj = rm.plm_m_oid
   and x.plm_leftobj = '917F410F954446F59DD3DB2F5D9B3247'
 order by rm.plm_m_id

select max(plm_completeddate)
 from
PLM_BPMv_WORKITEM

------解决方案--------------------

把PLM_BPMv_WORKITEM w这个表，用一条SQL子查贸易来代替，相当于一个视图，在这里过滤掉重复数据即可。
SQL code
(SELECT * 
FROM PLM_BPMv_WORKITEM 
WHERE (plm_processinstanceid,plm_completeddate) IN
      (SELECT plm_processinstanceid,MAX(plm_completeddate) FROM PLM_BPMv_WORKITEM 
 GROUP BY plm_processinstanceid)) w

------解决方案--------------------
做一个子查询，
例如：
SQL code
select * from PLM_BPMv_WORKITEM where plm_processinstanceid in (select plm_processinstanceid,max(dplm_completeddate) from PLM_BPMv_WORKITEM group by plm_processinstanceid )