sql别名无效

select riid,cid,...from (...)rei left join (select ots.riid,sum(ots.ormoney) ormoney,ots.orexcuse,ots.ortype from (select o.riid,o.ortype,rt.rtname,o.orexcuse,o.ormoney from otherreimburse o left join reimbursetype rt on rt.rtname=o.ortype) ots group by ots.riid,ots.orexcuse,ots.ortype)   otsr   on rei.riid = otsr.riid and rei.cid = otsr.orexcuse 

otsr怎么就总提示无效呢 别名 sql
[解决办法]

SELECT RIID, CID,.. .FROM(.. .) REI
  LEFT JOIN (SELECT OTS.RIID,
                    SUM(OTS.ORMONEY) ORMONEY,
                    OTS.OREXCUSE,
                    OTS.ORTYPE
               FROM (SELECT O.RIID,
                            O.ORTYPE,
                            RT.RTNAME,
                            O.OREXCUSE,
                            O.ORMONEY
                       FROM OTHERREIMBURSE O
                       LEFT JOIN REIMBURSETYPE RT ON RT.RTNAME = O.ORTYPE) OTS
              GROUP BY OTS.RIID, OTS.OREXCUSE, OTS.ORTYPE) OTSR ON REI.RIID =
                                                                   OTS.RIID
                                                               AND REI.CID =
                                                                   OTS.OREXCUSE 
 

[解决办法]
太长了，没有看完。给你个建议，一层层的查询。
先把最内的查出来，再逐个的往里面嵌套，就知道是哪里出错了。