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

В этом примере метод Move используется для позиционирования указателя записи на основе вводимых пользователем данных.This example uses the Move method to position the record pointer based on user input.

'BeginMoveVB  
  
    'To integrate this code  
    'replace the data source and initial catalog values  
    'in the connection string  
  
Public Sub Main()  
    On Error GoTo ErrorHandler  
  
    ' connection and recordset variables  
    Dim rstAuthors As ADODB.Recordset  
    Dim Cnxn As ADODB.Connection  
    Dim strCnxn As String  
    Dim strSQLAuthors As String  
     ' record variables  
    Dim varBookmark As Variant  
    Dim strCommand As String  
    Dim lngMove As Long  
  
    ' Open connection  
    Set Cnxn = New ADODB.Connection  
    strCnxn = "Provider='sqloledb';Data Source='MySqlServer';" & _  
        "Initial Catalog='Pubs';Integrated Security='SSPI';"  
    Cnxn.Open strCnxn  
  
    ' Open recordset from Authors table  
    Set rstAuthors = New ADODB.Recordset  
    rstAuthors.CursorLocation = adUseClient  
    ' Use client cursor to allow use of AbsolutePosition property  
    strSQLAuthors = "SELECT au_id, au_fname, au_lname, city, state FROM Authors ORDER BY au_lname"  
    rstAuthors.Open strSQLAuthors, strCnxn, adOpenStatic, adLockOptimistic, adCmdText  
  
    rstAuthors.MoveFirst  
  
    Do  
        ' Display information about current record and  
        ' ask how many records to move  
  
        strCommand = InputBox( _  
            "Record " & rstAuthors.AbsolutePosition & _  
            " of " & rstAuthors.RecordCount & vbCr & _  
            "Author: " & rstAuthors!au_fname & _  
            " " & rstAuthors!au_lname & vbCr & _  
            "Location: " & rstAuthors!city & _  
            ", " & rstAuthors!State & vbCr & vbCr & _  
            "Enter number of records to Move " & _  
            "(positive or negative).")  
  
          ' this is for exiting the loop  
        'lngMove = CLng(strCommand)  
  
        lngMove = CLng(Val(strCommand))  
        If lngMove = 0 Then  
            MsgBox "You either entered a non-number or canceled the input box. Exit the application."  
            Exit Do  
        End If  
  
        ' Store bookmark in case the Move goes too far  
        ' forward or backward  
        varBookmark = rstAuthors.Bookmark  
  
        ' Move method requires parameter of data type Long  
        rstAuthors.Move lngMove  
  
        ' Trap for BOF or EOF  
        If rstAuthors.BOF Then  
            MsgBox "Too far backward! Returning to current record."  
            rstAuthors.Bookmark = varBookmark  
        End If  
        If rstAuthors.EOF Then  
            MsgBox "Too far forward!  Returning to current record."  
            rstAuthors.Bookmark = varBookmark  
        End If  
    Loop  
  
    ' clean up  
    rstAuthors.Close  
    Cnxn.Close  
    Set rstAuthors = Nothing  
    Set Cnxn = Nothing  
    Exit Sub  
  
ErrorHandler:  
    ' clean up  
    If Not rstAuthors Is Nothing Then  
        If rstAuthors.State = adStateOpen Then rstAuthors.Close  
    End If  
    Set rstAuthors = 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  
'EndMoveVB  

См. такжеSee Also

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