DataTable Demo using the Compute() Method

This demo illustrates using the DataTable's Compute() method to return the average number of views for all FAQs that were added after a user-specified date.


Compute the average number of views for FAQs after a specified date:

FAQIDDescriptionViewCountFAQCategoryIDSubmittedByNameSubmittedByEmailDateEnteredCatName
181How can I format numbers and date/times using ASP.NET? For example, I want to format a number as a currency.96470222Scott Mitchellmitchell@4guysfromrolla.com1/19/2002 3:12:07 PMASP.NET
161How can I convert a Recordset into an array? Also, how can I convert an array into a Recordset?2380891Scott Mitchellmitchell@4guysfromrolla.com6/14/2001 5:02:02 PMArrays
115I am using Access and getting a 80004005 error (or a [Microsoft][ODBC Microsoft Access Driver] The Microsoft Jet database engine cannot open the file '(unknown)' error) when trying to open a connection! How can I fix this problem?23353021Scott Mitchellmitchell@4guysfromrolla.com1/17/2001 11:38:49 PMDatabases, Errors
83How can I quickly sort a VBScript array? 2300331Richard Lowechadich@yahoo.com11/12/2000 1:58:41 AMArrays
190How do I display data on a web page using arrays instead of Do...While...MoveNext...???...1860061Scott Mitchellmitchell@4guysfromrolla.com4/11/2002 1:14:41 PMArrays
106How can I find out if a record already exists in a database? If it doesn't, I want to add it.18351112Steve Ciminosteve_cimino@hotmail.com12/14/2000 4:59:11 PMDatabases, Queries
118When I get a list of all files in a directory via the FileSystemObject, they aren't ordered in any reasonable way. How can I sort the files by name? Or by size? Or by date created? Or... 1687504Bill Wilkinsonbill@ClearviewDesign.com1/22/2001 5:10:01 PMFileSystemObject
30For session variables to work, must the Web visitor have cookies enabled?1336356Scott Mitchellmitchell@4guysfromrolla.com9/26/2000 11:13:06 PMSession Object
14Can I send emails without using CDONTS?13032210Scott Mitchellmitchell@4guysfromrolla.com9/24/2000 1:18:37 AMEmail
149How can I remove multiple spaces between words in a string? That is, if I have: Hi    there how can I get: Hi there?1295572Scott Mitchellmitchell@4guysfromrolla.com3/31/2001 5:02:54 PMStrings


Source Code

<%@ Import Namespace="System.Data" %>
<%@ Import Namespace="System.Data.SqlClient" %>

<script language="VB" runat="server">
  Sub Page_Load(sender as Object, e as EventArgs)
    If Not Page.IsPostBack then
      'Create the DataTable
      Dim dt as DataTable = GetData()
      
      'Bind the DataTable to the DataGrid
      dgPeople.DataSource = dt
      dgPeople.DataBind()
    End If      
  End Sub

  Function GetData() as DataTable
      Dim dt as New DataTable()
      
      Dim myConnection as New SqlConnection(Connection String)
    
      Const strSQL as String = "sp_Popularity"
      Dim myCommand as New SqlCommand(strSQL, myConnection)

      Dim myAdapter as New SqlDataAdapter(myCommand)
      myAdapter.Fill(dt)

      Return dt 
  End Function  
  
  Sub DisplayStats(sender as Object, e as EventArgs)
    'Compute the avg.
    Dim dt as DataTable = GetData()
    
    Dim result as Object = dt.Compute("AVG(ViewCount)", "DateEntered > '" & FAQDate.Text & "'")
    Dim avg as Single = 0.0
    
    If Not result.Equals(DBNull.Value) then
      avg = Convert.ToSingle(result)
    End If
    
    Results.Text = "Average Views: " & avg
  End Sub

</script>

	<form runat="server">
		Compute the average number of views for FAQs after a specified date:
		<asp:TextBox runat="server" id="FAQDate" />
		<asp:Button Text="Compute" runat="server" OnClick="DisplayStats" />
		<br />
		<asp:Label id="Results" runat="server" />
	</form>
	<p>
	<asp:DataGrid runat="server" id="dgPeople"
		HeaderStyle-BackColor="LightGray"
		HeaderStyle-Font-Bold="True" />
		


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