Supports 方法范例 (VB)

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xSupports 方法范例 (VB)

本范例使用 Supports 方法来显示用不同游标类型打开的记录集所支持的选项。运行此过程需要 DisplaySupport 过程。

Public Sub SupportsX()

    Dim aintCursorType(4) As Integer
    Dim rsttitles As ADODB.Recordset
    Dim strCnn As String
    Dim intIndex As Integer

    ' Open connections.
        strCnn = "Provider=sqloledb;" & _
        "Data Source=srv;Initial Catalog=Pubs;User Id=sa;Password=; "

    ' Fill array with CursorType constants.
    aintCursorType(0) = adOpenForwardOnly
    aintCursorType(1) = adOpenKeyset
    aintCursorType(2) = adOpenDynamic
    aintCursorType(3) = adOpenStatic
   
    ' Open recordset using each CursorType and
    ' optimistic locking. Then call the DisplaySupport
    ' procedure to display the supported options.
    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 intIndex

End Sub

Public Sub DisplaySupport(rstTemp As ADODB.Recordset)

    Dim alngConstants(11) As Long
    Dim booSupports As Boolean
    Dim intIndex As Integer

    ' Fill array with cursor option constants.
    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 intIndex

End Sub

 

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