看到了有个sql语句 居然后面带+号，第一次看到就查了下
select
t1.seq, t1.ID imid, t1.workdate, t1.plancode, t1.linestr, t1.workstastr, t1.WORKSTACODE, t1.workitem, t1.impact, t1.pgorgtype, s.orgnum, t2.PLAN_START_TIME AS PLANSTARTTIME, t3.id sdid, t3.SD_ML, t3.in_fhpersons SNPERSONID, t3.FLOW_STATE, t4.FLOW_STATE JXFLOW_STATE, p.pgorgid, t4.id jxsid from wxu_t_tc_import t1, wxu_t_tc_wc t2, wxu_t_sdsq t3, SYS_T_ORG s, wxu_t_jxssq t4, wxu_nn_t_pg p where 1 = 1 and t1.isdiscard = '0' and t1.id = t2.wxid(+) and t1.id = t3.TCID(+) and t1.id = t4.TCID(+) and (t1.zrgqid = s.id or (t1.zrgqid is null and t1.phzrgqid = s.id)) and t1.id = p.tcid(+) and s.orgnum like '010202%' and t1.workdate >= '2016-11-18' and t1.workdate <= '2016-11-18' and (t1.plantype!=2 or t1.plantype is null) order by t1.seq, t1.workdate （+）：含义：这个关联关系，可有，可无；不影响主表数据的查询。