MDAC 2.5 SDK - ADO


 

GetRows Method Example (VB)

See Also

This example uses the GetRows method to retrieve a specified number of rows from a Recordset and to fill an array with the resulting data. The GetRows method will return fewer than the desired number of rows in two cases: either if EOF has been reached, or if GetRows tried to retrieve a record that was deleted by another user. The function returns False only if the second case occurs. The GetRowsOK function is required for this procedure to run.

Public Sub GetRowsX()

   Dim rstEmployees As ADODB.Recordset
   Dim strCnn As String
   Dim strMessage As String
   Dim intRows As Integer
   Dim avarRecords As Variant
   Dim intRecord As Integer

   ' Open recordset with names and hire dates from employee table.
      strCnn = "Provider=sqloledb;" & _
      "Data Source=srv;Initial Catalog=Pubs;User Id=sa;Password=; "
   Set rstEmployees = New ADODB.Recordset
   rstEmployees.Open "SELECT fName, lName, hire_date " & _
      "FROM Employee ORDER BY lName", strCnn, , , adCmdText

   Do While True
      ' Get user input for number of rows.
      strMessage = "Enter number of rows to retrieve."
      intRows = Val(InputBox(strMessage))

      If intRows <= 0 Then Exit Do

      ' If GetRowsOK is successful, print the results,
      ' noting if the end of the file was reached.
      If GetRowsOK(rstEmployees, intRows, _
            avarRecords) Then
         If intRows > UBound(avarRecords, 2) + 1 Then
            Debug.Print "(Not enough records in " & _
               "Recordset to retrieve " & intRows & _
               " rows.)"
         End If
         Debug.Print UBound(avarRecords, 2) + 1 & _
            " records found."

         ' Print the retrieved data.
         For intRecord = 0 To UBound(avarRecords, 2)
            Debug.Print "  " & _
               avarRecords(0, intRecord) & " " & _
               avarRecords(1, intRecord) & ", " & _
               avarRecords(2, intRecord)
         Next intRecord
      Else
         ' Assuming the GetRows error was due to data 
         ' changes by another user, use Requery to
         ' refresh the Recordset and start over.
         If MsgBox("GetRows failed--retry?", _
               vbYesNo) = vbYes Then
            rstEmployees.Requery
         Else
            Debug.Print "GetRows failed!"
            Exit Do
         End If
      End If

      ' Because using GetRows leaves the current 
      ' record pointer at the last record accessed, 
      ' move the pointer back to the beginning of the 
      ' Recordset before looping back for another search.
      rstEmployees.MoveFirst
   Loop

   rstEmployees.Close

End Sub

Public Function GetRowsOK(rstTemp As ADODB.Recordset, _
   intNumber As Integer, avarData As Variant) As Boolean

   ' Store results of GetRows method in array.
   avarData = rstTemp.GetRows(intNumber)
   ' Return False only if fewer than the desired 
   ' number of rows were returned, but not because the 
   ' end of the Recordset was reached.
   If intNumber > UBound(avarData, 2) + 1 And _
         Not rstTemp.EOF Then
      GetRowsOK = False
   Else
      GetRowsOK = True
   End If

End Function