Filter and RecordCount Properties Example (ADO)


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Filter and RecordCount Properties Example

This example uses the Filter property to open a new Recordset based on a specified condition applied to an existing Recordset. It uses the RecordCount property to show the number of records in the two Recordsets. The FilterField function is required for this procedure to run.

Public Sub FilterX()

	Dim rstPublishers As ADODB.Recordset
	Dim rstPublishersCountry As ADODB.Recordset
	Dim strCnn As String
	Dim intPublisherCount As Integer
	Dim strCountry As String
	Dim strMessage As String

	' Open recordset with data from Publishers table.
	strCnn = "driver={SQL Server};server=srv;" & _
		"uid=sa;pwd=;database=pubs"
	Set rstPublishers = New ADODB.Recordset
	rstPublishers.CursorType = adOpenStatic
	rstPublishers.Open "publishers", strCnn, , , adCmdTable

	' Populate the Recordset.
	intPublisherCount = rstPublishers.RecordCount

	' Get user input.
	strCountry = Trim(InputBox( _
		"Enter a country to filter on:"))

	If strCountry <> "" Then
		' Open a filtered Recordset object.
		Set rstPublishersCountry = _
			FilterField(rstPublishers, "Country", strCountry)

		If rstPublishersCountry.RecordCount = 0 Then
			MsgBox "No publishers from that country."
		Else
			' Print number of records for the original
			' Recordset object and the filtered Recordset
			' object.
			strMessage = "Orders in original recordset: " & _
				vbCr & intPublisherCount & vbCr & _
				"Orders in filtered recordset (Country = '" & _
				strCountry & "'): " & vbCr & _
				rstPublishersCountry.RecordCount
			MsgBox strMessage
		End If
		rstPublishersCountry.Close

	End If

End Sub

Public Function FilterField(rstTemp As ADODB.Recordset, _
	strField As String, strFilter As String) As ADODB.Recordset

	' Set a filter on the specified Recordset object and then
	' open a new Recordset object.
	rstTemp.Filter = strField & " = '" & strFilter & "'"
	Set FilterField = rstTemp

End Function

Note When you know the data you want to select, it's usually more efficient to open a Recordset with an SQL statement. This example shows how you can create just one Recordset and obtain records from a particular country.

Public Sub FilterX2()

	Dim rstPublishers As ADODB.Recordset
	Dim strCnn As String

	' Open recordset with data from Publishers table.
	strCnn = "driver={SQL Server};server=srv;" & _
		"uid=sa;pwd=;database=pubs"
	Set rstPublishers = New ADODB.Recordset
	rstPublishers.CursorType = adOpenStatic
	rstPublishers.Open "SELECT * FROM publishers " & _
		"WHERE Country = 'USA'", strCnn, , , adCmdText
		
	' Print current data in recordset.
	rstPublishers.MoveFirst
	Do While Not rstPublishers.EOF
		Debug.Print rstPublishers!pub_name & ", " & _
			rstPublishers!country
		rstPublishers.MoveNext
	Loop

	rstPublishers.Close

End Sub