Sql 在select子句中添加额外列时返回不同记录数的Oracle脚本

我的脚本执行有问题。下面的脚本在我的数据库中返回744条记录，但如果我在添加“cnt”列为select list时重新编写此脚本，此脚本将返回740条记录，尝试了很多次，但在“select子句”中添加额外列时找不到减少结果行数的原因

它返回740条记录

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需要知道导致此问题的可能原因

请给出表的DDL和显示问题的最小工作数据样本（最好是insert语句）（这是在中创建最小工作示例的良好资源）。不选择任何列的情况下，计数（*）是多少？也给出第二个完整的查询。应该有一些区别。因为select子句终于运行了。在此之前，所有连接/位置/组/按顺序完成。因此，仅更改select查询不会理想地更改结果。如果是这样，我会非常惊讶。尝试使用+规则提示运行这两个查询。Oracle中有几个错误，不同的exec计划导致错误的查询结果。顺便问一下，db的版本是什么？不是11gR1吗？@ibre5041:是的DB版本是11gR1。@Utsav:我同样感到惊讶，因为cnt列不在初始选择列表中，而是在where子句中使用，如[nvl（cnt，0）2]，为了查看cnt有什么值，我在select中添加了cnt，令人惊讶的是，结果计数发生了变化，然后我通过从select中添加和删除cnt对其进行了多次测试，结果发生了变化。

Select NVL(E.Employee_Ident, '-') EmpId,
   Z.EmpLastName || ', ' || z.EmpFirstname EmpName,
   z.DOB,
   z.EmpPersonId,
   z.DepPersonId,
   NVL(z.PlanType, 131999) PlanType,
   z.Empstat,
   z.Status  from (Select ML.personid EmpPersonId,
           EL.personid elpersonid,
           EL.plantype elplantype,
           Ml.plantype mlplantype,
           ML.name_last EmpLastName,
           ML.name_first EmpFirstName,
           EL.DepId DepPersonId,
           EL.name_last DepLastName,
           EL.name_first DepFirstName,
           ML.plantype PlanType,
           ML.EmpStat,
           NVL(EL.status, 2) Status,
           NVL(to_char(EL.Birthdate, 'mm/dd/yyyy'), '-') DOB,
           sum(case
                 when status = 0 or status = 1 or EmpStat = 1 or EmpStat = 2 then
                  1
                 else
                  0
               end) over(partition by DepId) Cnt
      from (select DCES.*,
                   cfm.employee_personid PersonId,
                   Dep.Name_Last,
                   Dep.Name_First,
                   Dep.Personid          DepId,
                   Dep.Birthdate
              from (select ChildId,
                           v2.plantype PlanType,
                           nvl(v1.status, v2.status) status
                      from (select d.family_member_personid ChildId,
                                   d.plantype               PlanType,
                                   d.status                 status
                              from cb_enrollment_status d
                             where d.employee_personid <>
                                   d.family_member_personid
                               and d.enrollment_type <> 120008
                               and d.plantype in (131001, 131002)) v1 partition by(v1.ChildId)
                     right outer join (select 131001 plantype, 2 status
                                        from dual
                                      union all
                                      select 131002 plantype, 2 status
                                        from dual) v2
                        on (v1.plantype = v2.plantype)) DCES,
                   cb_person dep,
                   cb_family_member cfm
             where cfm.family_member_personid = DCES.ChildId(+)
               and cfm.delete_status = 0
               and cfm.special_enrollee <> 1
               and cfm.family_member_personid = Dep.personid) EL,
           (select p.personid,
                   p.name_last,
                   p.name_first,
                   v2.plantype PlanType,
                   nvl(v1.status, v2.status) Empstat
              from cb_person p,
                   (select s.employee_personid PersonId,
                           s.plantype          PlanType,
                           s.status            status
                      from cb_enrollment_status s
                     where s.employee_personid = s.family_member_personid
                       and s.enrollment_type <> 120008
                       and s.employee_personid in
                           (select distinct employee_personid
                              from cb_family_member
                             where delete_status = 0
                               and special_enrollee <> 1)
                       and s.status in (0, 1)
                       and s.plantype in (131001, 131002)) v1 partition by(v1.personid)
             right outer join (select 131001 plantype, 2 status
                                from dual
                              union all
                              select 131002 plantype, 2 status from dual) v2
                on (v1.plantype = v2.plantype)
             where p.personid = v1.personid) ML
     where ML.Personid = EL.Personid(+)
       and ML.PlanType = NVL(EL.PlanType, ML.PlanType)) Z,
   (select distinct *
      from (select e.Employee_Ident,
                   personid,
                   change_sequence,
                   max(change_sequence) over(partition by personid) r
              from cb_employee e
             where coalesce(E.Hiredate_Rehire,
                            E.Hiredate_Original,
                            to_date(to_char(sysdate, 'MM/DD/YYYY'),
                                    'MM/DD/YYYY')) <=
                   to_date(to_char(sysdate, 'MM/DD/YYYY'), 'MM/DD/YYYY'))
     where change_sequence = r) E where e.personid = z.emppersonid  order by lower(z.EmpLastName),
      lower(z.EmpFirstName),
      z.EmpPersonId,
      lower(z.DepLastName),
      lower(z.DepFirstName),
      z.DepPersonId,
      z.PlanType 

Select NVL(E.Employee_Ident, '-') EmpId,
   Z.EmpLastName || ', ' || z.EmpFirstname EmpName,
   z.DOB,
   z.EmpPersonId,
   z.DepPersonId,
   NVL(z.PlanType, 131999) PlanType,
   z.Empstat,
   z.Status, Z.cnt