## Using FusionCharts with ASP > Creating Drill-down charts
In our previous example, we had used FusionCharts to plot a chart using data stored in database. We'll now extend that example itself to create a drill-down chart which can show more information. If you recall from previous example, we were showing the sum of factory output in a pie chart as under:
In this example, we'll extend this example, so that when a user clicks on a pie slice for a factory, he can drill down to see date wise production for that factory.
Setting up the pie chart for Link
To set up the pie chart to enable links for drill-down involves just minor tweaking of our previous BasicDBExample.asp. We basically need to add the link attribute for each <set> element. We create a new page Default.asp from the previous page in DBExample folder with the following code changes:
<%@ Language=VBScript %> <HTML> <HEAD> <TITLE> FusionCharts - Database and Drill-Down Example </TITLE> <SCRIPT LANGUAGE="Javascript" SRC="../../FusionCharts/FusionCharts.js"></SCRIPT> </HEAD> <!-- #INCLUDE FILE="../Includes/FusionCharts.asp" --> <!-- #INCLUDE FILE="../Includes/DBConn.asp" --> <BODY> <% 'In this example, we show how to connect FusionCharts to a database. 'For the sake of ease, we've used an Access database which is present in '../DB/FactoryDB.mdb. It just contains two tables, which are linked to each 'other. 'Database Objects - Initialization Dim oRs, oRs2, strQuery 'strXML will be used to store the entire XML document generated Dim strXML 'Create the recordset to retrieve data Set oRs = Server.CreateObject("ADODB.Recordset") 'Generate the chart element strXML = "<chart caption='Factory Output report' subCaption='By Quantity' pieSliceDepth='30' showBorder='1' formatNumberScale='0' numberSuffix=' Units' >" 'Iterate through each factory strQuery = "select * from Factory_Master" Set oRs = oConn.Execute(strQuery) While Not oRs.Eof 'Now create second recordset to get details for this factory Set oRs2 = Server.CreateObject("ADODB.Recordset") strQuery = "select sum(Quantity) as TotOutput from Factory_Output where FactoryId=" & ors("FactoryId") Set oRs2 = oConn.Execute(strQuery) 'Generate <set label='..' value='..' link='..' /> 'Note that we're setting link as Detailed.asp?FactoryId=<<FactoryId>> and then URL Encoding it strXML = strXML & "<set label='" & ors("FactoryName") & "' value='" & ors2("TotOutput") & "' link='" & Server.URLEncode("Detailed.asp?FactoryId=" & ors("FactoryId")) & "'/>" 'Close recordset Set oRs2 = Nothing oRs.MoveNext Wend 'Finally, close <chart> element strXML = strXML & "</chart>" Set oRs = nothing 'Create the chart - Pie 3D Chart with data from strXML Call renderChart("../../FusionCharts/Pie3D.swf", "", strXML, "FactorySum", 600, 300, false, false) %> </BODY> </HTML>
As you can see in the code above, we're doing the following: Include FusionCharts.js JavaScript class and FusionCharts.asp , to enable easy embedding of FusionCharts. We then include DBConn.asp, which contains connection parameters to connect to Access database. Thereafter, we generate the XML data document by iterating through the recordset. We store the XML data in strXML variable. To each <set> element, we add the link attribute, which points to Detailed.asp - the page that contains the chart to show details. We pass the factory id of the respective factory by appending it to the link. We finally URL Encode the link, which is a very important step. Finally, we render the chart using renderChart() method and pass strXML as dataXML. Let's now shift our attention to Detailed.asp page.
Creating the detailed data chart page
The page Detailed.asp contains the following code:
<%@ Language=VBScript %> <HTML> <HEAD> <TITLE> FusionCharts - Database and Drill-Down Example </TITLE> <SCRIPT LANGUAGE="Javascript" SRC="../../FusionCharts/FusionCharts.js"></SCRIPT> </HEAD> <!-- #INCLUDE FILE="../Includes/FusionCharts.asp" --> <!-- #INCLUDE FILE="../Includes/DBConn.asp" --> <BODY> <% 'This page is invoked from Default.asp. When the user clicks on a pie 'slice in Default.asp, the factory Id is passed to this page. We need 'to get that factory id, get information from database and then show 'a detailed chart. 'First, get the factory Id Dim FactoryId 'Request the factory Id from Querystring FactoryId = Request.QueryString("FactoryId") Dim oRs, strQuery 'strXML will be used to store the entire XML document generated Dim strXML, intCounter intCounter = 0 Set oRs = Server.CreateObject("ADODB.Recordset") 'Generate the chart element string strXML = "<chart palette='2' caption='Factory " & FactoryId &" Output ' subcaption='(In Units)' xAxisName='Date' showValues='1' labelStep='2' >" 'Now, we get the data for that factory strQuery = "select * from Factory_Output where FactoryId=" & FactoryId Set oRs = oConn.Execute(strQuery) While Not oRs.Eof 'Here, we convert date into a more readable form for set label. strXML = strXML & "<set label='" & datePart("d",ors("DatePro")) & "/" & datePart("m",ors("DatePro")) & "' value='" & ors("Quantity") & "'/>" Set oRs2 = Nothing oRs.MoveNext Wend 'Close <chart> element strXML = strXML & "</chart>" Set oRs = nothing 'Create the chart - Column 2D Chart with data from strXML Call renderChart("../../FusionCharts/Column2D.swf", "", strXML, "FactoryDetailed", 600, 300, false, false) %> </CENTER> </BODY> </HTML>
In this page, we're: Including FusionCharts.js JavaScript class and FusionCharts.asp , to enable easy embedding of FusionCharts. Requesting the factory id for which we've to show detailed data. This data was sent to us as querystring, as a part of pie chart link. We get the requisite data for this factory from database and then convert it into XML using string concatenation. Finally, we render a Column 2D chart using renderChart() method to show detailed data. When you now run the app, you'll see the detailed page as under: