Ejemplo de los métodos MoveFirst, MoveLast, MoveNext y MovePrevious (VB)

Se aplica a: Access 2013, Office 2013

En este ejemplo se usan los métodos MoveFirst, MoveLast, MoveNext y MovePrevious para mover el puntero de registro de un objeto Recordset en función del comando proporcionado. Se requiere el procedimiento de MoveAny para que pueda ejecutarse este procedimiento.

 
'BeginMoveFirstVB 
 
 '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 
 ' record variables 
 Dim strMessage As String 
 Dim intCommand As Integer 
 
 ' 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 enable AbsolutePosition property 
 strSQLAuthors = "Authors" 
 rstAuthors.Open strSQLAuthors, Cnxn, adOpenStatic, adLockReadOnly, adCmdTable 
 
 ' Show current record information and get user's method choice 
 Do 
 strMessage = "Name: " & rstAuthors!au_fname & " " & _ 
 rstAuthors!au_lname & vbCr & "Record " & _ 
 rstAuthors.AbsolutePosition & " of " & _ 
 rstAuthors.RecordCount & vbCr & vbCr & _ 
 "[1 - MoveFirst, 2 - MoveLast, " & vbCr & _ 
 "3 - MoveNext, 4 - MovePrevious]" 
 intCommand = Val(Left(InputBox(strMessage), 1)) 
 
 ' for exiting the loop 
 If intCommand < 1 Or intCommand > 4 Then 
 MsgBox "You either entered a non-number or canceled the input box. Exit the application." 
 Exit Do 
 End If 
 
 ' Use specified method while trapping for BOF and EOF 
 Select Case intCommand 
 Case 1 
 rstAuthors.MoveFirst 
 Case 2 
 rstAuthors.MoveLast 
 Case 3 
 rstAuthors.MoveNext 
 If rstAuthors.EOF Then 
 MsgBox "Already at end of recordset!" 
 rstAuthors.MoveLast 
 End If 
 Case 4 
 rstAuthors.MovePrevious 
 If rstAuthors.BOF Then 
 MsgBox "Already at beginning of recordset!" 
 rstAuthors.MoveFirst 
 End If 
 End Select 
 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 
 
'EndMoveFirstVB