Esempio del metodo Move (VB)
In questo esempio si usa il metodo Move per posizionare il puntatore del record in base all'input dell'utente.
'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