我正在为我有限（但增长缓慢）的数据库和编程知识构建一个相当复杂的数据库。所以，我真的很感谢你的帮助。
该数据库跟踪客户、建筑物、房间和房间中的设备。
我有一个搜索表单，它过滤了我所做的几乎整个数据库的联合查询。SQL如下：
SELECT tblcustomer.organizationfk,
tblcustomer.shopnamefk,
tblcustomer.officesymfk,
tblcustomer.lastname,
tblcustomer.firstname,
tblfacilitymgr.buildingfk,
tblrooms.roomspk,
tblbuilding.buildingname,
tblrooms.roomname,
tblcabinet.cabinetname,
tblequipment.cabinetfk,
tblequipment.equipmentnamefk,
tblequipment.equipmentbrandfk,
tblequipment.equipmentnetworktypefk
FROM ((tblbuilding
INNER JOIN tblrooms
ON tblbuilding.buildingpk = tblrooms.buildingfk)
INNER JOIN (tblcustomer
INNER JOIN tblfacilitymgr
ON tblcustomer.customerpk =
tblfacilitymgr.customerfk)
ON tblbuilding.buildingpk = tblfacilitymgr.buildingfk)
LEFT JOIN (tblcabinet
LEFT JOIN tblequipment
ON tblcabinet.cabinetpk = tblequipment.cabinetfk)
ON tblrooms.roomspk = tblcabinet.roomsfk
UNION
SELECT tblcustomer.organizationfk,
tblcustomer.shopnamefk,
tblcustomer.officesymfk,
tblcustomer.lastname,
tblcustomer.firstname,
tblrooms.buildingfk,
tblrooms.roomspk,
tblbuilding.buildingname,
tblrooms.roomname,
tblcabinet.cabinetname,
tblequipment.cabinetfk,
tblequipment.equipmentnamefk,
tblequipment.equipmentbrandfk,
tblequipment.equipmentnetworktypefk
FROM ((tblbuilding
INNER JOIN tblrooms
ON tblbuilding.buildingpk = tblrooms.buildingfk)
LEFT JOIN (tblcabinet
LEFT JOIN tblequipment
ON tblcabinet.cabinetpk = tblequipment.cabinetfk)
ON tblrooms.roomspk = tblcabinet.roomsfk)
INNER JOIN (tblcustomer
INNER JOIN tblroomspoc
ON tblcustomer.customerpk = tblroomspoc.customerfk)
ON tblrooms.roomspk = tblroomspoc.roomsfk;
搜索表单如下所示：
cmdsearch 的代码在这里：
Option Compare Database
Option Explicit 'always set this It will point out errors with field/vaiable names
Private Sub cboSearchLastName_AfterUpdate()
Me.cboSearchFirstName.Requery
End Sub
Private Sub cboSearchOrganization_AfterUpdate()
Me.cboSearchShopName.Requery
End Sub
Private Sub cboSearchShopName_AfterUpdate()
Me.cboSearchOfficeSym.Requery
End Sub
Private Sub cmdReset_Click()
Me.cboSearchBuildingName = ""
Me.cboSearchRoomName = ""
Me.cboSearchOrganization = ""
Me.cboSearchShopName = ""
Me.cboSearchOfficeSym = ""
Me.cboSearchLastName = ""
Me.cboSearchFirstName = ""
Me.FilterOn = False
End Sub
Private Sub txtBuildingID_AfterUpdate()
Me.lstFacilityMgr.Requery
End Sub
Private Sub txtRoomsID_AfterUpdate()
Me.lstRoomsPOC.Requery
End Sub
Private Sub cmdSearch_Click()
Dim strWhere As String
Dim lngLen As Long
Dim startStr As String
If Not IsNullOrEmpty(Me.cboSearchLastName) Then
startStr = IIf(strWhere = "", "", " AND ")
strWhere = strWhere & startStr & "[LastName] ='" & Me.cboSearchLastName & "'"
End If
If Not IsNullOrEmpty(Me.cboSearchFirstName) Then
startStr = IIf(strWhere = "", "", " AND ")
strWhere = strWhere & startStr & "[FirstName] ='" & Me.cboSearchFirstName & "'"
End If
If Not IsNullOrEmpty(Me.cboSearchOrganization) Then
startStr = IIf(strWhere = "", "", " AND ")
strWhere = strWhere & startStr & "[OrganizationFK] =" & Me.cboSearchOrganization
End If
If Not IsNullOrEmpty(Me.cboSearchShopName) Then
startStr = IIf(strWhere = "", "", " AND ")
strWhere = strWhere & startStr & "[ShopNameFK] =" & Me.cboSearchShopName
End If
If Not IsNullOrEmpty(Me.cboSearchOfficeSym) Then
startStr = IIf(strWhere = "", "", " AND ")
strWhere = strWhere & startStr & "[OfficeSymFK] =" & Me.cboSearchOfficeSym
End If
If Not IsNullOrEmpty(Me.cboSearchBuildingName) Then
startStr = IIf(strWhere = "", "", " AND ")
strWhere = strWhere & startStr & "[BuildingFK] =" & Me.cboSearchBuildingName
End If
If Not IsNullOrEmpty(Me.cboSearchRoomName) Then
startStr = IIf(strWhere = "", "", " AND ")
strWhere = strWhere & startStr & "[RoomsPK] =" & Me.cboSearchRoomName
End If
If Not IsNullOrEmpty(Me.cboSearchEquipmentName) Then
startStr = IIf(strWhere = "", "", " AND ")
strWhere = strWhere & startStr & "[EquipmentNameFK] =" & Me.cboSearchEquipmentName
End If
If Not IsNullOrEmpty(Me.cboSearchEquipmentSerialNo) Then
startStr = IIf(strWhere = "", "", " AND ")
strWhere = strWhere & startStr & "[SerialNoFK] =" & Me.cboSearchEquipmentSerialNo
End If
Call MsgBox(strWhere, vbOKOnly, "Debug")
lngLen = Len(strWhere) - 5
If lngLen <= 0 Then
MsgBox "No criteria", vbInformation, "Nothing to do."
Else
'strWhere = Left$(strWhere, lngLen)
MsgBox strWhere
If DCount("*", "qryRecordSet", strWhere) = 0 Then
MsgBox "No corresponding records to your search criteria." & vbCrLf & vbCrLf
Me.FilterOn = False
Me.cboSearchBuildingName = ""
Me.cboSearchRoomName = ""
Me.cboSearchOrganization = ""
Me.cboSearchShopName = ""
Me.cboSearchOfficeSym = ""
Me.cboSearchLastName = ""
Me.cboSearchFirstName = ""
Else
Me.Filter = strWhere
Me.FilterOn = True
End If
End If
End Sub
Function IsNullOrEmpty(val As Variant) As Boolean
'First conditional validates for Nothing
'Second condition validates for an Empty String situation "" or " "
Dim ret As Boolean: ret = False
If IsMissing(val) Then
ret = True
ElseIf (val Is Nothing) Then
ret = True
ElseIf (val & vbNullString = vbNullString) Then
ret = True
ElseIf (Len(Trim(val)) <= 0) Then
ret = True
End If
IsNullOrEmpty = ret
End Function
我的搜索表单完美运行。我遇到的问题是某些搜索返回重复的结果。这是因为联合查询包含重复的结果。我不知道如何生成包含我需要的所有信息的查询，并且不会产生重复的结果。因为，一个客户可以是多个建筑物的设施经理，所以一栋建筑物可以有多个设施经理。一个客户可以是多个房间的联系人，一个房间可以有多个 POC。设备只能在一个房间里。
澄清一下，如果 Building "A", room "1100" 有三个 POC，那么如果我搜索 building A, room 1100 我会看到三个结果。我只需要看到一个结果。
我的表单上有两个文本框（隐藏以便用户看不到它们）。txtBuildingID 和 txtRoomsID。表单上的所有其他内容都基于这两个文本框进行查询。我需要这两个文本框的组合是唯一的。那是因为，如果我只搜索“A”楼并且 A 楼有三个房间，我应该会看到 Building ID 1 / Room ID 1... Building ID 1 / Room ID 2 等。
这样做的原因是因为我想使用多个条件进行过滤，但只显示一个唯一的建筑物 ID/房间 ID。这是因为如果我搜索“Smith”并且他是 A 栋 1100 室的 POC，我想查看该建筑物/房间以及有关该房间的所有信息。因为，如果史密斯不接电话，我可以打电话给“琼斯”。
我不在乎哪条记录被删除，只要我在两个文本框之间有唯一的记录。我对SQL知之甚少，但据我所知，我认为这不能用SQL来完成。我想我可能需要使用 DCount 来计算记录，然后删除重复项。我不知道该怎么做。我在谷歌上花了几天时间，我什至还没有接近解决方案。充其量，如果我的语法正确，我可以计算重复的数量（buildingfk 和 roompk 之间的唯一记录超过 1 条），但是我不确定如何删除重复。或者，如果我需要指定要删除的重复项。就个人而言，只要他们被删除，我不在乎。
我问了一个非常擅长编程的朋友，这让他很难过。他建议我在这里问。所以我真的很感谢你在这里的帮助。 询问
