在我的前端数据库，我有几个来自多个后端数据库的链接表。我怎样才能确保所有表打开时前端连接？
你可以通过TableDefs集合，看看哪些表具有连接属性集。如果填充连接，重新使用字符串中指定的数据库表。
这里是一个函数（fRefreshLinks），可以在数据库启动运行。功能看起来在每个数据库中的表中的代码运行，并试图找到该表的数据源连接属性填充。
如果链接表指定的数据库不存在，就会有GetOpenFileName对话框，使用户可以选择的替代来源。
'***************** Code Start ***************
' This code was originally written by Dev Ashish.
' It is not to be altered or distributed,
' except as part of an application.
' You are free to use it in any application,
' provided the copyright notice is left unchanged.
'
' Code Courtesy of
' Dev Ashish
'
Function fRefreshLinks() As Boolean
Dim strMsg As String, collTbls As Collection
Dim i As Integer, strDBPath As String, strTbl As String
Dim dbCurr As DATABASE, dbLink As DATABASE
Dim tdfLocal As TableDef
Dim varRet As Variant
Dim strNewPath As String
Const cERR_USERCANCEL = vbObjectError + 1000
Const cERR_NOREMOTETABLE = vbObjectError + 2000
On Local Error GoTo fRefreshLinks_Err
If MsgBox("Are you sure you want to reconnect all Access tables?", _
vbQuestion + vbYesNo, "Please confirm...") = vbNo Then Err.Raise cERR_USERCANCEL
'First get all linked tables in a collection
Set collTbls = fGetLinkedTables
'now link all of them
Set dbCurr = CurrentDb
strMsg = "Do you wish to specify a different path for the Access Tables?"
If MsgBox(strMsg, vbQuestion + vbYesNo, "Alternate data source...") = vbYes Then
strNewPath = fGetMDBName("Please select a new datasource")
Else
strNewPath = vbNullString
End If
For i = collTbls.Count To 1 Step -1
strDBPath = fParsePath(collTbls(i))
strTbl = fParseTable(collTbls(i))
varRet = SysCmd(acSysCmdSetStatus, "Now linking '" & strTbl & "'....")
If Left$(strDBPath, 4) = "ODBC" Then
'ODBC Tables
'ODBC Tables handled separately
' Set tdfLocal = dbCurr.TableDefs(strTbl)
' With tdfLocal
' .Connect = pcCONNECT
' .RefreshLink
' collTbls.Remove (strTbl)
' End With
Else
If strNewPath <> vbNullString Then
'Try this first
strDBPath = strNewPath
Else
If Len(Dir(strDBPath)) = 0 Then
'File Doesn't Exist, call GetOpenFileName
strDBPath = fGetMDBName("'" & strDBPath & "' not found.")
If strDBPath = vbNullString Then
'user pressed cancel
Err.Raise cERR_USERCANCEL
End If
End If
End If
'backend database exists
'putting it here since we could have
'tables from multiple sources
Set dbLink = DBEngine(0).OpenDatabase(strDBPath)
'check to see if the table is present in dbLink
strTbl = fParseTable(collTbls(i))
If fIsRemoteTable(dbLink, strTbl) Then
'everything's ok, reconnect
Set tdfLocal = dbCurr.TableDefs(strTbl)
With tdfLocal
.Connect = ";Database=" & strDBPath
.RefreshLink
collTbls.Remove (.Name)
End With
Else
Err.Raise cERR_NOREMOTETABLE
End If
End If
Next
fRefreshLinks = True
varRet = SysCmd(acSysCmdClearStatus)
MsgBox "All Access tables were successfully reconnected.", _
vbInformation + vbOKOnly, _
"Success"
fRefreshLinks_End:
Set collTbls = Nothing
Set tdfLocal = Nothing
Set dbLink = Nothing
Set dbCurr = Nothing
Exit Function
fRefreshLinks_Err:
fRefreshLinks = False
Select Case Err
Case 3059:
Case cERR_USERCANCEL:
MsgBox "No Database was specified, couldn't link tables.", _
vbCritical + vbOKOnly, _
"Error in refreshing links."
Resume fRefreshLinks_End
Case cERR_NOREMOTETABLE:
MsgBox "Table '" & strTbl & "' was not found in the database" & _
vbCrLf & dbLink.Name & ". Couldn't refresh links", _
vbCritical + vbOKOnly, _
"Error in refreshing links."
Resume fRefreshLinks_End
Case Else:
strMsg = "Error Information..." & vbCrLf & vbCrLf
strMsg = strMsg & "Function: fRefreshLinks" & vbCrLf
strMsg = strMsg & "Description: " & Err.Description & vbCrLf
strMsg = strMsg & "Error #: " & Format$(Err.Number) & vbCrLf
MsgBox strMsg, vbOKOnly + vbCritical, "Error"
Resume fRefreshLinks_End
End Select
End Function
Function fIsRemoteTable(dbRemote As DATABASE, strTbl As String) As Boolean
Dim tdf As TableDef
On Error Resume Next
Set tdf = dbRemote.TableDefs(strTbl)
fIsRemoteTable = (Err = 0)
Set tdf = Nothing
End Function
Function fGetMDBName(strIn As String) As String
'Calls GetOpenFileName dialog
Dim strFilter As String
strFilter = ahtAddFilterItem(strFilter, _
"Access Database(*.mdb;*.mda;*.mde;*.mdw) ", _
"*.mdb; *.mda; *.mde; *.mdw")
strFilter = ahtAddFilterItem(strFilter, _
"All Files (*.*)", _
"*.*")
fGetMDBName = ahtCommonFileOpenSave(Filter:=strFilter, _
OpenFile:=True, _
DialogTitle:=strIn, _
Flags:=ahtOFN_HIDEREADONLY)
End Function
Function fGetLinkedTables() As Collection
'Returns all linked tables
Dim collTables As New Collection
Dim tdf As TableDef, db As DATABASE
Set db = CurrentDb
db.TableDefs.Refresh
For Each tdf In db.TableDefs
With tdf
If Len(.Connect) > 0 Then
If Left$(.Connect, 4) = "ODBC" Then
' collTables.Add Item:=.Name & ";" & .Connect, KEY:=.Name
'ODBC Reconnect handled separately
Else
collTables.Add Item:=.Name & .Connect, Key:=.Name
End If
End If
End With
Next
Set fGetLinkedTables = collTables
Set collTables = Nothing
Set tdf = Nothing
Set db = Nothing
End Function
Function fParsePath(strIn As String) As String
If Left$(strIn, 4) <> "ODBC" Then
fParsePath = Right(strIn, Len(strIn) _
- (InStr(1, strIn, "DATABASE=") + 8))
Else
fParsePath = strIn
End If
End Function
Function fParseTable(strIn As String) As String
fParseTable = Left$(strIn, InStr(1, strIn, ";") - 1)
End Function
'***************** Code End ***************
转自：http://access.mvps.org/access/tables/tbl0009.htm
