麻烦各位老师给看看这条SQL语句的问题出在哪里？
select distinct a.diqu,a.kahao,a.CheckInNo,a.piaolei,a.ZhengJian,a.CheckInTime,a.RenShu,b.mingcheng,c.mingma,d.mingcheng as mch,e.mingcheng as pl,f.DFMingCheng as zj,g.Expr1 as cf from(select k.CheckInTime,k.RenShu,k.diqu,k.kahao,k.checkinno,k.piaolei,k.ZhengJian from Tbl_checkIn k,(select max(id) as id,zhengjian from Tbl_checkIn group by zhengjian) b where k.id=b.id) a,tbl_diqu b,tbl_ShouPiao c,tbl_YanPiaoDian d,tbl_PiaoLei e,Tbl_SFZ f,zgUser.tbl_S g where a.diqu=b.bianhao and a.KaHao=c.kahao and a.CheckInNo=d.bianhao and left(a.zhengjian,6)=f.SFZBianHao and a.piaolei=e.bianhao and a.ZhengJian=g.ZhengJian and mingma>='18001' and mingma<='18205' order by a.ZhengJian


首先说下这条语句是朋友帮我写的，我的学艺不精，麻烦各位老师帮忙看下这个语句，之前没加g.Expr1、zgUser.tbl_S g，a.ZhengJian=g.ZhengJian这三句是能查出数据的，但是加完后就不显示结果了，也没有报错查询结果为空，g.Expr1表项是证件的使用次数，a.ZhengJian=g.ZhengJian这个筛选条件写法有错误吗？请各位老师帮忙给看下，谢谢啦！

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引用:

SQL code
SELECT DISTINCT
a.diqu ,
a.kahao ,
a.CheckInNo ,
a.piaolei ,
a.ZhengJian ,
a.CheckInTime ,
a.RenShu ,
b.mingcheng ,
c……


但是a表和g表之间zhengjian列的值确实有相同的，g表里记录的是证件和使……