Пример метода Clone (Visual Basic)Clone Method Example (VB)

В этом примере используется метод clone для создания копий набора записей , а затем пользователь помещает указатель записи каждой копии независимо друг от друга.This example uses the Clone method to create copies of a Recordset and then lets the user position the record pointer of each copy independently.

    'To integrate this code  
    'replace the data source and initial catalog values  
    'in the connection string  
Public Sub Main()  
    On Error GoTo ErrorHandler  
    'recordset array and connection variables  
    Dim arstStores(1 To 3) As ADODB.Recordset  
    Dim Cnxn As ADODB.Connection  
    Dim strSQLStore As String  
    Dim strCnxn As String  
     'record variables  
    Dim intLoop As Integer  
    Dim strMessage As String  
    Dim strFind As String  
    ' Open a connection  
    Set Cnxn = New ADODB.Connection  
    strCnxn = "Provider='sqloledb';Data Source='MySqlServer';" & _  
        "Initial Catalog='Pubs';Integrated Security='SSPI';"  
    Cnxn.Open strCnxn  
    ' Open recordset as a static cursor type recordset  
    Set arstStores(1) = New ADODB.Recordset  
    strSQLStore = "SELECT stor_name FROM Stores ORDER BY stor_name"  
    arstStores(1).Open strSQLStore, strCnxn, adOpenStatic, adLockBatchOptimistic, adCmdText  
    ' Create two clones of the original Recordset  
    Set arstStores(2) = arstStores(1).Clone  
    Set arstStores(3) = arstStores(1).Clone  
    ' Loop through the array so that on each pass the user  
    ' is searching a different copy of the same Recordset  
        For intLoop = 1 To 3  
             ' Ask for search string while showing where  
             ' the current record pointer is for each Recordset  
            strMessage = _  
                "Recordsets from stores table:" & vbCr & _  
                "  1 - Original - Record pointer at " & arstStores(1)!stor_name & vbCr & _  
                "  2 - Clone - Record pointer at " & arstStores(2)!stor_name & vbCr & _  
                "  3 - Clone - Record pointer at " & arstStores(3)!stor_name & vbCr & _  
                "Enter search string for #" & intLoop & ":"  
            strFind = Trim(InputBox(strMessage))  
             ' make sure something was entered, if not then EXIT loop  
            If strFind = "" Then Exit Do  
             ' otherwise locate the record from the entered string  
            arstStores(intLoop).Filter = "stor_name = '" & strFind & "'"  
             'if there's no match, jump to the last record  
            If arstStores(intLoop).EOF Then  
                arstStores(intLoop).Filter = adFilterNone  
                MsgBox "Found " & strFind  
            End If  
        Next intLoop  
    ' clean up  
    Set arstStores(1) = Nothing  
    Set arstStores(2) = Nothing  
    Set arstStores(3) = Nothing  
    Set Cnxn = Nothing  
    Exit Sub  
    ' clean up  
    If Not arstStores(1) Is Nothing Then  
        If arstStores(1).State = adStateOpen Then arstStores(1).Close  
    End If  
    Set arstStores(1) = Nothing  
    If Not arstStores(2) Is Nothing Then  
        If arstStores(2).State = adStateOpen Then arstStores(2).Close  
    End If  
    Set arstStores(2) = Nothing  
    If Not arstStores(3) Is Nothing Then  
        If arstStores(3).State = adStateOpen Then arstStores(3).Close  
    End If  
    Set arstStores(3) = Nothing  
    If Not Cnxn Is Nothing Then  
        If Cnxn.State = adStateOpen Then Cnxn.Close  
    End If  
    Set Cnxn = Nothing  
    If Err <> 0 Then  
        MsgBox Err.Source & "-->" & Err.Description, , "Error"  
    End If  
End Sub  

См. такжеSee Also

Метод Clone (ADO) Clone Method (ADO)
Объект Recordset (ADO)Recordset Object (ADO)