Supports 方法范例

该范例使用 Supports 方法,显示用不同游标类型打开的记录集所支持的选项。运行该过程需要 DisplaySupport 过程。

Public Sub SupportsX()   Dim aintCursorType(4) As Integer
   Dim rstTitles As ADODB.Recordset
   Dim strCnn As String
   Dim intIndex As Integer   ' 打开连接。
      strCnn = "Provider=sqloledb;" & _
      "Data Source=srv;Initial Catalog=pubs;User Id=sa;Password=; "   ' 使用 CursorType 常量填充数组。
   aintCursorType(0) = adOpenForwardOnly
   aintCursorType(1) = adOpenKeyset
   aintCursorType(2) = adOpenDynamic
   aintCursorType(3) = adOpenStatic
   
   ' 使用每个 CursorType 和优化锁定打开记录集,
   ' 然后调用 DisplaySupport 过程显示所支持的选项。
   For intIndex = 0 To 3
      Set rstTitles = New ADODB.Recordset
      rstTitles.CursorType = aintCursorType(intIndex)
      rstTitles.LockType = adLockOptimistic
      rstTitles.Open "titles", strCnn, , , adCmdTable
      
      Select Case aintCursorType(intIndex)
         Case adOpenForwardOnly
            Debug.Print "ForwardOnly cursor supports:"
         Case adOpenKeyset
            Debug.Print "Keyset cursor supports:"
         Case adOpenDynamic
            Debug.Print "Dynamic cursor supports:"
         Case adOpenStatic
            Debug.Print "Static cursor supports:"
      End Select      DisplaySupport rstTitles
      rstTitles.Close
   Next intIndexEnd SubPublic Sub DisplaySupport(rstTemp As ADODB.Recordset)   Dim alngConstants(11) As Long
   Dim booSupports As Boolean
   Dim intIndex As Integer   ' 用游标选项常量填充数组。
   alngConstants(0) = adAddNew
   alngConstants(1) = adApproxPosition
   alngConstants(2) = adBookmark
   alngConstants(3) = adDelete
   alngConstants(4) = adFind
   alngConstants(5) = adHoldRecords
   alngConstants(6) = adMovePrevious
   alngConstants(7) = adNotify
   alngConstants(8) = adResync
   alngConstants(9) = adUpdate
   alngConstants(10) = adUpdateBatch
   
   For intIndex = 0 To 10
      booSupports = _
         rstTemp.Supports(alngConstants(intIndex))
      If booSupports Then
         Select Case alngConstants(intIndex)
            Case adAddNew
               Debug.Print "   AddNew"
            Case adApproxPosition
               Debug.Print "   AbsolutePosition and AbsolutePage"
            Case adBookmark
               Debug.Print "   Bookmark"
            Case adDelete
               Debug.Print "   Delete"
            Case adFind
               Debug.Print "   Find"
            Case adHoldRecords
               Debug.Print "   Holding Records"
            Case adMovePrevious
               Debug.Print "   MovePrevious and Move"
            Case adNotify
               Debug.Print "   Notifications"
            Case adResync
               Debug.Print "   Resyncing data"
            Case adUpdate
               Debug.Print "   Update"
            Case adUpdateBatch
               Debug.Print "   batch updating"
         End Select
      End If
   Next intIndexEnd Sub
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