Move メソッドの例 (VB)
この例では、Move メソッドを使って、ユーザー入力に基づいてレコード ポインターを配置します。
'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