Exemples de méthodes MoveFirst, MoveLast, MoveNext, et MovePrevious (VB)
Cet exemple utilise les méthodes MoveFirst, MoveLast, MoveNext et MovePrevious pour déplacer le pointeur d’enregistrement d’un Recordset en fonction de la commande fournie. La procédure MoveAny est requise pour que cette procédure s’exécute.
'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
Voir aussi
MoveFirst, MoveLast, MoveNext et MovePrevious, méthodes (ADO)
Recordset, objet (ADO)