MS Access SQL - 当 WHERE 语句引用第一个查询时如何合并 2 个查询

Question

一些详细信息：Query1 returns 行重复，但 DispositionID 值除外。我只想要具有最高 DispositionID 值的行。

简化示例：

查询 1 returns:
DispositionID [姓氏] [名字]
0 史密斯鲍勃
1422 史密斯鲍勃
0 亚历山大格兰特
0 纳布尔贝蒂

我想要的：
DispositionID [姓氏] [名字]
1422 史密斯鲍勃
0 亚历山大格兰特
0 纳布尔贝蒂

感谢您的指导。我很难让聚合函数正常工作，似乎在 Query2 中为 Query1 使用别名 Q1 应该可以解决问题，但我也无法正常工作。

我试过的和详细的实际查询：

我一直在努力想办法将以下 2 个查询组合成一个查询，但是当我使用别名时，SQL 出现错误。是否可以将这 2 个查询合并为一个查询，还是我必须使用 2 个单独的查询？

查询 1:

SELECT tblCLient_Dispositions.DispositionID, tblClients.[Last Name], tblClients.[First Name], tblClients.[Date of Contact], tblCLient_Dispositions.StartDate, tblCLient_Dispositions.DispositionStatusID, tblStudentStatus.StudentStatus, tblStudentStatus.StudentProfessor, tblStudentStatus.ProfessorEmail, (SELECT COUNT(*) 
      FROM 
(
SELECT tblClient_Disp_Appointments.DispositionID, 
tblClient_Disp_Appointments.ApptTypeID, 
tblClient_Disp_Appointments.ApptStatusID, 
tblClient_Disp_Appointments.ApptDate, 
tblroomSchedule.RoomID 
FROM (tblClient_Disp_Appointments  
LEFT JOIN tblroomSchedule ON tblClient_Disp_Appointments.AppointmentID = tblroomSchedule.ApptID) 
WHERE (RoomID <> 6) 
AND (ApptTypeID = 23 OR ApptTypeID = 18 OR ApptTypeID = 3 OR ApptTypeID = 11 OR ApptTypeID = 6 OR ApptTypeID = 19 OR ApptTypeID = 2) 
AND (ApptStatusID = 3)
)
WHERE (DispositionID = tblCLient_Dispositions.DispositionID) 
     ) AS SessionsCompleted, tblStudentStatus.SessionsRequired, CDate(forms!frmProfessorReport.tbxStartingDate) AS WhatYear
FROM (tblCLient_Dispositions LEFT JOIN tblClients ON tblCLient_Dispositions.ClientID = tblClients.ClientID) LEFT JOIN tblStudentStatus ON tblClients.University_Student = tblStudentStatus.StudentStatusID
WHERE (((tblClients.University_Student)=[forms]![frmProfessorReport].[cbxWhichClass]) AND ((Nz(Year([tblCLients].[Date of Contact]),Year([forms]![frmProfessorReport].[tbxStartingDate])))=Year([forms]![frmProfessorReport].[tbxStartingDate])))
ORDER BY tblClients.[Last Name]

UNION

SELECT 0 AS DispositionID, tblClients.[Last Name], tblClients.[First Name], tblClients.[Date of Contact], Null AS StartDate, 0 AS DispositionStatusID, tblStudentStatus.StudentStatus, tblStudentStatus.StudentProfessor, tblStudentStatus.ProfessorEmail, 0 AS SessionsCompleted, tblStudentStatus.SessionsRequired, CDate(forms!frmProfessorReport.tbxStartingDate) AS WhatYear
FROM tblClients LEFT JOIN tblStudentStatus ON tblClients.University_Student = tblStudentStatus.StudentStatusID
WHERE (((tblClients.University_Student)=[forms]![frmProfessorReport].[cbxWhichClass]) 
     AND ((Nz(Year([tblCLients].[Date of Contact]),Year([forms]![frmProfessorReport].[tbxStartingDate])))=Year([forms]![frmProfessorReport].[tbxStartingDate])))
ORDER BY tblClients.[Last Name]

查询 2:

SELECT * 
FROM Query1 
WHERE DispositionID = (SELECT MAX(DispositionID) FROM Query1 AS lookup WHERE lookup.[Last Name] & lookup.[First Name] & lookup.[Date of Contact] = Query1.[Last Name] & Query1.[First Name] & Query1.[Date of Contact])

我想做的是将 Query1 粘贴到 "Query1" 中，其中 Query2 表示 "FROM Query1" 然后给它一个 Q1 的别名，但是我在 Query2 的 WHERE 子句中得到一个错误Access 找不到 Q1。（当然，我在运行组合查询SQL之前将WHERE子句中的引用从Query1改为Q1。）

Answer 1

根据您的简化示例，您似乎想要：

select max(DispositionID), [Last Name], [First Name]
from t
group by [Last Name], [First Name]

MS Access SQL - 当 WHERE 语句引用第一个查询时如何合并 2 个查询

MS Access SQL - how to combine 2 queries when the WHERE statement references the first query

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