Execute, Requery, and Clear Methods Example (VB)

This example demonstrates the Execute method when run from both a Command object and a Connection object. It also uses the Requery method to retrieve current data in a Recordset, and the Clear method to clear the contents of the Errors collection. (The Errors collection is accessed via the Connection object of the ActiveConnection property of the Recordset.) The ExecuteCommand and PrintOutput procedures are required for this procedure to run.

'BeginExecuteVB
Public Sub ExecuteX()

   Dim strSQLChange As String
   Dim strSQLRestore As String
   Dim strCnn As String
   Dim cnn1 As ADODB.Connection
   Dim cmdChange As ADODB.Command
   Dim rstTitles As ADODB.Recordset
   Dim errLoop As ADODB.Error

   ' Define two SQL statements to execute as command text.
   strSQLChange = "UPDATE Titles SET Type = " & _
      "'self_help' WHERE Type = 'psychology'"
   strSQLRestore = "UPDATE Titles SET Type = " & _
      "'psychology' WHERE Type = 'self_help'"

   ' Open connection.
      strCnn = "Provider=sqloledb;" & _
      "Data Source=MyServer;Initial Catalog=Pubs;User Id=sa;Password=; "
   Set cnn1 = New ADODB.Connection
   cnn1.Open strCnn

   ' Create command object.
   Set cmdChange = New ADODB.Command
   Set cmdChange.ActiveConnection = cnn1
   cmdChange.CommandText = strSQLChange
   
   ' Open titles table.
   Set rstTitles = New ADODB.Recordset
   rstTitles.Open "titles", cnn1, , , adCmdTable

   ' Print report of original data.
   Debug.Print _
      "Data in Titles table before executing the query"
   PrintOutput rstTitles

   ' Clear extraneous errors from the Errors collection.
   cnn1.Errors.Clear

   ' Call the ExecuteCommand subroutine to execute cmdChange command.
   ExecuteCommand cmdChange, rstTitles
   
   ' Print report of new data.
   Debug.Print _
      "Data in Titles table after executing the query"
   PrintOutput rstTitles

   ' Use the Connection object's execute method to
   ' execute SQL statement to restore data. Trap for
   ' errors, checking the Errors collection if necessary.
   On Error GoTo Err_Execute
   cnn1.Execute strSQLRestore, , adExecuteNoRecords
   On Error GoTo 0

   ' Retrieve the current data by requerying the recordset.
   rstTitles.Requery

   ' Print report of restored data.
   Debug.Print "Data after executing the query " & _
      "to restore the original information"
   PrintOutput rstTitles

   rstTitles.Close
   cnn1.Close
   
   Exit Sub
   
Err_Execute:

   ' Notify user of any errors that result from
   ' executing the query.
   If rstTitles.ActiveConnection.Errors.count >= 0 Then
      For Each errLoop In rstTitles.ActiveConnection.Errors
         MsgBox "Error number: " & errLoop.Number & vbCr & _
            errLoop.Description
      Next errLoop
   End If
   Resume Next

End Sub

Public Sub ExecuteCommand(cmdTemp As ADODB.Command, _
   rstTemp As ADODB.Recordset)

   Dim errLoop As Error
   
   ' Run the specified Command object. Trap for
   ' errors, checking the Errors collection if necessary.
   On Error GoTo Err_Execute
   cmdTemp.Execute
   On Error GoTo 0

   ' Retrieve the current data by requerying the recordset.
   rstTemp.Requery
   
   Exit Sub

Err_Execute:

   ' Notify user of any errors that result from
   ' executing the query.
   If rstTemp.ActiveConnection.Errors.count > 0 Then
      For Each errLoop In rstTemp.ActiveConnection.Errors
         MsgBox "Error number: " & errLoop.Number & vbCr & _
            errLoop.Description
      Next errLoop
   End If
   
   Resume Next

End Sub

Public Sub PrintOutput(rstTemp As ADODB.Recordset)

   ' Enumerate Recordset.
   Do While Not rstTemp.EOF
      Debug.Print "  " & rstTemp!title & _
         ", " & rstTemp!Type
      rstTemp.MoveNext
   Loop

End Sub
'EndExecuteVB

Execute, Requery, and Clear Methods Example (VB)

See Also