Update および CancelUpdate メソッドの例 (VB)
この例では、Update メソッドと CancelUpdate メソッドを組み合わせて説明します。
'BeginUpdateVB
Public Sub Main()
On Error GoTo ErrorHandler
'To integrate this code
'replace the data source and initial catalog values
'in the connection string
' recordset and connection variables
Dim rstEmployees As ADODB.Recordset
Dim Cnxn As ADODB.Connection
Dim strCnxn As String
Dim strSQLEmployees As String
' buffer variables
Dim strOldFirst As String
Dim strOldLast 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 to enable changes
Set rstEmployees = New ADODB.Recordset
strSQLEmployees = "SELECT fname, lname FROM Employee ORDER BY lname"
rstEmployees.Open strSQLEmployees, Cnxn, adOpenKeyset, adLockOptimistic, adCmdText
' Store original data
strOldFirst = rstEmployees!fname
strOldLast = rstEmployees!lname
' Change data in edit buffer
rstEmployees!fname = "Linda"
rstEmployees!lname = "Kobara"
' Show contents of buffer and get user input
strMessage = "Edit in progress:" & vbCr & _
" Original data = " & strOldFirst & " " & _
strOldLast & vbCr & " Data in buffer = " & _
rstEmployees!fname & " " & rstEmployees!lname & vbCr & vbCr & _
"Use Update to replace the original data with " & _
"the buffered data in the Recordset?"
If MsgBox(strMessage, vbYesNo) = vbYes Then
rstEmployees.Update
Else
rstEmployees.CancelUpdate
End If
' show the resulting data
MsgBox "Data in recordset = " & rstEmployees!fname & " " & _
rstEmployees!lname
' restore original data because this is a demonstration
If Not (strOldFirst = rstEmployees!fname And _
strOldLast = rstEmployees!lname) Then
rstEmployees!fname = strOldFirst
rstEmployees!lname = strOldLast
rstEmployees.Update
End If
' clean up
rstEmployees.Close
Cnxn.Close
Set rstEmployees = Nothing
Set Cnxn = Nothing
Exit Sub
ErrorHandler:
' clean up
If Not rstEmployees Is Nothing Then
If rstEmployees.State = adStateOpen Then rstEmployees.Close
End If
Set rstEmployees = 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
' EndUpdateVB
この例では、Update メソッドと AddNew メソッドを組み合わせて説明します。
Attribute VB_Name = "Update"