Esempio dei metodi UpdateBatch e CancelBatch (VB)
Questo esempio illustra i metodi UpdateBatch e CancelBatch.
'BeginUpdateBatchVB
Public Sub Main()
On Error GoTo ErrorHandler
'To integrate this code
'replace the data source and initial catalog values
'in the connection string
'connection and recordset variables
Dim rstTitles As ADODB.Recordset
Dim Cnxn As ADODB.Connection
Dim strCnxn As String
Dim strSQLTitles As String
'record variables
Dim strTitle As String
Dim strMessage As String
' Open connection
Set Cnxn = New ADODB.Connection
strCnxn = "Provider='sqloledb';Data Source='MySqlServer';" & _
"Initial Catalog='Pubs';Integrated Security='SSPI';"
Cnxn.Open strCnxn
' open recordset for batch update
Set rstTitles = New ADODB.Recordset
strSQLTitles = "titles"
rstTitles.Open strSQLTitles, Cnxn, adOpenKeyset, adLockBatchOptimistic, adCmdTable
rstTitles.MoveFirst
' Loop through recordset and ask user if she wants
' to change the type for a specified title.
Do Until rstTitles.EOF
If Trim(rstTitles!Type) = "psychology" Then
strTitle = rstTitles!Title
strMessage = "Title: " & strTitle & vbCr & _
"Change type to self help?"
If MsgBox(strMessage, vbYesNo) = vbYes Then
rstTitles!Type = "self_help"
End If
End If
rstTitles.MoveNext
Loop
' Ask the user if she wants to commit to all the
' changes made above.
If MsgBox("Save all changes?", vbYesNo) = vbYes Then
rstTitles.UpdateBatch
Else
rstTitles.CancelBatch
End If
' Print current data in recordset.
rstTitles.Requery
rstTitles.MoveFirst
Do While Not rstTitles.EOF
Debug.Print rstTitles!Title & " - " & rstTitles!Type
rstTitles.MoveNext
Loop
' Restore original values because this is a demonstration.
rstTitles.MoveFirst
Do Until rstTitles.EOF
If Trim(rstTitles!Type) = "self_help" Then
rstTitles!Type = "psychology"
End If
rstTitles.MoveNext
Loop
rstTitles.UpdateBatch
' clean up
rstTitles.Close
Cnxn.Close
Set rstTitles = Nothing
Set Cnxn = Nothing
Exit Sub
ErrorHandler:
' clean up
If Not rstTitles Is Nothing Then
If rstTitles.State = adStateOpen Then rstTitles.Close
End If
Set rstTitles = 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
'EndUpdateBatchVB