我们正在升级使用 SQL Server 作为其数据存储的访问数据库存在问题。
这个特定的数据库链接到 2 个 sql 数据库，所以我想简化一下，我们在主数据库中有一个视图，它链接到辅助数据库中的每个表。这样一来，访问只需要直接与一个 SQL 数据库对话。
当我们链接对数据库视图的访问时，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，并且链接视图因为主键信息丢失而变为只读。
有没有办法在保留主键信息的同时刷新视图链接？
约翰
【问题讨论】：
标签： sql sql-server ms-access views
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，它存储了我重新连接所需的所有信息。如果你实现了这个功能，你就不必担心连接到多个 SQL 数据库，因为每个要重新连接的表都有自己的连接字符串，这可以顺利处理。
当您接近尾声时，您会看到我使用 DAO 通过 db.Execute "CREATE INDEX " & sPrimaryKeyName & " ON " & sLocalTableName & "(" & sPrimaryKeyField & ")WITH PRIMARY;" 重新创建主键
如果您有任何问题，请提出。
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
【讨论】：
大量将访问表重新链接到 SQL Server 的 DSN 较少的代码通常会先删除链接，然后再重新创建链接。然后代码设置连接字符串。因此，正是删除导致您丢失了主键曾经/现在的内容。
我实际上建议您修改重新链接代码，以免删除表链接。
尝试类似：
For Each tdfCurrent In dbCurrent.TableDefs
If Len(tdfCurrent.Connect) > 0 Then
If Left$(tdfCurrent.Connect, 5) = "ODBC;" Then
strCon = "ODBC;DRIVER={sql server};" & _
"SERVER=" & ServerName & ";" & _
"DATABASE=" & DatabaseName & ";" & _
"UID=" & UserID & ";" & _
"PWD=" & USERpw & ";" & _
"APP=Microsoft Office 2003;" & _
"WSID=" & WSID & ";"
End If
End If
tdfCurrent.Connect = strCon
tdfCurrent.RefreshLink
End If
Next tdfCurrent
【讨论】：
这对我来说效果好一点（注意移动端 if's）：
Dim dbCurrent As Database
Set dbCurrent = CurrentDb()
StatusList.SetFocus
StatusList.AddItem ("starting... ")
I = DoEvents()
Dim tdfCurrent As DAO.TableDef
For Each tdfCurrent In dbCurrent.TableDefs
If Len(tdfCurrent.Connect) > 0 Then
If Left$(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。
【讨论】：