Question

我们遇到了一个访问数据库的问题，我们正在升级以使用SQL Server作为其数据存储。

这个特定的数据库链接到2个sql数据库，所以我想简化一些事情，我们在主数据库中有一个链接到辅助数据库中每个表的视图。这样访问只需要直接与一个SQL数据库通信。

当我们链接访问数据库视图时，我们选择哪些字段是主键，因此视图不是只读的。我们有标准代码，当数据库打开以获取任何更改时，刷新所有链接，并且链接视图变为只读，因为主键信息丢失。

是否有办法在保留主键信息的同时刷新视图链接？

约翰

Answer 1

我在下面包含了我的整个ODBC重新连接功能。这个函数的前提是我有一个名为rtblODBC的表，它存储了重新连接所需的所有信息。如果您实现此功能，则无需担心连接到多个SQL数据库，因为可以顺利处理每个要重新连接的表并具有自己的连接字符串。

当你走到最后，你会看到我使用DAO用db.Execute“CREATE INDEX”＆amp ;;重新创建主键。 sPrimaryKeyName＆amp; “ON”＆amp; sLocalTableName＆amp; “（＆amp; sPrimaryKeyField＆amp;”）WITH PRIMARY;“

如果您有任何疑问，请询问。

Public Function fnReconnectODBC( _
    Optional bForceReconnect As Boolean _
    ) As Boolean
    ' Comments  :
    ' Parameters: bForceReconnect -
    ' Returns   : Boolean -
    ' Modified  :
    ' --------------------------------------------------'

    On Error GoTo Err_fnReconnectODBC

    Dim db As DAO.Database
    Dim rs As DAO.Recordset
    Dim tdf As DAO.TableDef
    Dim sPrimaryKeyName As String
    Dim sPrimaryKeyField As String
    Dim sLocalTableName As String
    Dim strConnect As String
    Dim varRet As Variant

    Dim con As ADODB.Connection
    Dim rst As ADODB.Recordset
    Dim sSQL As String

    If IsMissing(bForceReconnect) Then

        bForceReconnect = False

    End If

    sSQL = "SELECT rtblODBC.LocalTableName, MSysObjects.Name, MSysObjects.ForeignName, rtblODBC.SourceTableName, MSysObjects.Connect, rtblODBC.ConnectString " _
         & "FROM MSysObjects RIGHT JOIN rtblODBC ON MSysObjects.Name = rtblODBC.LocalTableName " _
         & "WHERE (((rtblODBC.ConnectString)<>'ODBC;' & [Connect]));"

    Set con = Access.CurrentProject.Connection
    Set rst = New ADODB.Recordset

    rst.Open sSQL, con, adOpenDynamic, adLockOptimistic

        'Test the recordset to see if any tables in rtblODBC (needed tables) are missing from the MSysObjects (actual tables)
        If rst.BOF And rst.EOF And bForceReconnect = False Then

            'No missing tables identified
            fnReconnectODBC = True

        Else

            'Table returned information, we don't have a perfect match, time to relink
            Set db = CurrentDb
            Set rs = db.OpenRecordset("rtblODBC", dbOpenSnapshot)

                'For each table definition in the database collection of tables
                For Each tdf In db.TableDefs

                    'Set strConnect variable to table connection string
                    strConnect = tdf.Connect

                    If Len(strConnect) > 0 And Left(tdf.Name, 1) <> "~" Then

                        If Left(strConnect, 4) = "ODBC" Then

                            'If there is a connection string, and it's not a temp table, and it IS an odbc table
                            'Delete the table
                            DoCmd.DeleteObject acTable, tdf.Name

                        End If

                    End If

                Next

                'Relink tables from rtblODBC
                With rs

                    .MoveFirst

                    Do While Not .EOF

                        Set tdf = db.CreateTableDef(!localtablename, dbAttachSavePWD, !SourceTableName, !ConnectString)

                        varRet = SysCmd(acSysCmdSetStatus, "Relinking '" & !SourceTableName & "'")

                        db.TableDefs.Append tdf
                        db.TableDefs.Refresh

                        If Len(!PrimaryKeyName & "") > 0 And Len(!PrimaryKeyField & "") > 0 Then

                            sPrimaryKeyName = !PrimaryKeyName
                            sPrimaryKeyField = !PrimaryKeyField
                            sLocalTableName = !localtablename

                            db.Execute "CREATE INDEX " & sPrimaryKeyName & " ON " & sLocalTableName & "(" & sPrimaryKeyField & ")WITH PRIMARY;"

                        End If

                        db.TableDefs.Refresh

                        .MoveNext

                    Loop

                End With

            subTurnOffSubDataSheets

            fnReconnectODBC = True

        End If

    rst.Close
    Set rst = Nothing

    con.Close
    Set con = Nothing


Exit_fnReconnectODBC:

    Set tdf = Nothing
    Set rs = Nothing
    Set db = Nothing

    varRet = SysCmd(acSysCmdClearStatus)

    Exit Function

Err_fnReconnectODBC:

    fnReconnectODBC = False

    sPrompt = "Press OK to continue."
    vbMsg = MsgBox(sPrompt, vbOKOnly, "Error Reconnecting")
    If vbMsg = vbOK Then

        Resume Exit_fnReconnectODBC

    End If

End Function

Answer 2

将访问表重新链接到SQL服务器的大量DSN代码通常先删除链接，然后重新创建链接。然后代码设置连接字符串。因此，删除会导致您失去主键是什么。

我实际上建议您修改重新链接代码，以便不删除表格链接。

尝试类似：

For Each tdfCurrent In dbCurrent.TableDefs
   If Len(tdfCurrent.Connect) > 0 Then
      If Left$(tdfCurrent.Connect, 5) = "ODBC;" Then
         strCon = "ODBC;DRIVER={sql server};" & _
           "SERVER=" & ServerName & ";" & _
           "DATABASE=" & DatabaseName & ";" & _
           "UID=" & UserID & ";" & _
           "PWD=" & USERpw & ";" & _
           "APP=Microsoft Office 2003;" & _
           "WSID=" & WSID & ";"
        End If
     End If
     tdfCurrent.Connect = strCon
     tdfCurrent.RefreshLink
  End If
Next tdfCurrent

Answer 3

这对我来说更合适（注意移动的结尾如果）：

Dim dbCurrent As Database
Set dbCurrent = CurrentDb()

StatusList.SetFocus
StatusList.AddItem ("starting... ")
I = DoEvents()
Dim tdfCurrent As DAO.TableDef
For Each tdfCurrent In dbCurrent.TableDefs
   If Len(tdfCurrent.Connect) > 0 Then
      If Left$(tdfCurrent.Connect, 5) = "ODBC;" Then
         strCon = "ODBC;DRIVER={sql server};" & _
           "SERVER=" & ServerName & ";" & _
           "DATABASE=" & DatabaseName & ";" & _
           "UID=" & UserID & ";" & _
           "PWD=" & USERpw & ";" & _
           "APP=Microsoft Office 2003;" & _
           "WSID=" & WSID & ";"

           StatusList.AddItem ("fixing " & tdfCurrent.Name)
        tdfCurrent.Connect = strCon
        tdfCurrent.RefreshLink
     End If
  End If
  I = DoEvents()
Next tdfCurrent

  StatusList.AddItem ("----Done.")

ODBC检查是正确的，即使“ODBC;”部分未显示在MSysObjects视图中。

MS Access链接到SQL Server视图

3 个答案: