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Ejemplo de la propiedad Optimize (VB)

En este ejemplo se muestra la propiedad dinámica Optimize del objeto Field. El campo zip de la tabla Authors de la base de datos Pubs no está indexado. Al establecer la propiedad Optimize en True en el campo zip, se autoriza a ADO a crear un índice que mejore el rendimiento del método Find.

'BeginOptimizeVB  
Public Sub Main()  
    On Error GoTo ErrorHandler  
  
    'To integrate this code  
    'replace the data source and initial catalog values  
    'in the connection string.  
  
    ' Declare the recordset and connection variables.  
    Dim Cnxn As ADODB.Connection  
    Dim rstAuthors As ADODB.Recordset  
    Dim strCnxn As String  
    Dim strSQLAuthors As String  
  
     ' Open connection.  
    strCnxn = "Provider='sqloledb';Data Source='MySqlServer';" & _  
        "Initial Catalog='Pubs';Integrated Security='SSPI';"  
    Set Cnxn = New ADODB.Connection  
    Cnxn.Open strCnxn  
  
     ' open recordset client-side to enable index creation.  
    Set rstAuthors = New ADODB.Recordset  
    rstAuthors.CursorLocation = adUseClient  
    strSQLAuthors = "SELECT * FROM Authors"  
    rstAuthors.Open strSQLAuthors, Cnxn, adOpenStatic, adLockReadOnly, adCmdText  
     ' Create the index.  
    rstAuthors!zip.Properties("Optimize") = True  
     ' Find Akiko Yokomoto  
    rstAuthors.Find "zip = '94595'"  
  
     ' Show results.  
    Debug.Print rstAuthors!au_fname & " " & rstAuthors!au_lname & " " & _  
             rstAuthors!address & " " & rstAuthors!city & " " & rstAuthors!State  
    rstAuthors!zip.Properties("Optimize") = False  'Delete the index.  
  
    ' 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  
'EndOptimizeVB  

Consulte también

Objeto Field
Propiedad dinámica Optimize (ADO)