## Using FusionCharts with ASP.NET 2.0 (VB.NET) > Plotting data from a database
In this section, we'll show you how to use FusionCharts and ASP.NET to plot charts from data contained in a database. We'll create a pie chart to show "Production by Factory" using: dataXML method first. Thereafter, we'll convert this chart to use dataURL method. For the sake of ease, we'll use an Access Database. The database is present in Download Package > Code > VB_NET > DB folder. You can, however, use any database with FusionCharts including MS SQL, Oracle, mySQL etc. Before you go further with this page, we recommend you to please see the previous section "Basic Examples" as we start off from concepts explained in that page. The code examples contained in this page are present in Download Package > Code > VB_NET > DBExample folder. The Access database is present in Download Package > Code > VB_NET > DB.
Database Structure
Before we code the ASP.NET pages to retrieve data, let's quickly have a look at the database structure.
The database contains just 2 tables: Factory_Master: To store the name and id of each factory Factory_Output: To store the number of units produced by each factory for a given date. For demonstration, we've fed some dummy data in the database. Let's now shift our attention to the ASP.NET page that will interact with the database, fetch data and then render a chart.
Building the ASP.NET Page for dataXML Method
The ASP.NET page for dataXML method example is named as BasicDBExample.aspx (in DBExample folder). It contains the following code (GetFactorySummaryChartHtml() method from code behind page also reproduced below):
<%@ Page Language="VB" AutoEventWireup="false" CodeFile="BasicDBExample.aspx.vb" Inherits="DBExample_BasicDBExample" %> <HTML> <HEAD> <TITLE>FusionCharts - Database Example </TITLE> <SCRIPT LANGUAGE="Javascript" SRC="../FusionCharts/FusionCharts.js"></SCRIPT> </HEAD> <body> <form id='form1' name='form1' method='post' runat="server"> <%=GetFactorySummaryChartHtml()%> </form> </body> </HTML>
Code Behind page: Imports InfoSoftGlobal Imports System.Text Imports DataConnection Partial Class DBExample_BasicDBExample Inherits System.Web.UI.Page Public Function GetFactorySummaryChartHtml() As String '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. 'xmlData will be used to store the entire XML document generated Dim xmlData As New StringBuilder() 'Generate the chart element xmlData.Append("<chart caption='Factory Output report' subCaption='By Quantity' pieSliceDepth='30' showBorder='1' formatNumberScale='0' numberSuffix=' Units'>") 'create recordset to get details for the factories Dim factoryQuery As String = "select a.FactoryId, a.FactoryName, sum(b.Quantity) as TotQ from .Factory_Master a, Factory_Output b where a.FactoryId=b.FactoryID group by a.FactoryId, a.FactoryName" ' Dim oRs As New DbConn(factoryQuery) 'Iterate through each record While oRs.ReadData.Read() 'Generate <set name='..' value='..' /> xmlData.Append("<set label='" & oRs.ReadData("FactoryName").ToString() & "' value='" & oRs.ReadData("TotQ").ToString & "' />") End While ' oRs.ReadData.Close() 'Close chart element xmlData = (xmlData &"</chart>") 'Create the chart - Pie 3D Chart with data from xmlData Return InfoSoftGlobal.FusionCharts.RenderChart("../FusionCharts/Pie3D.swf", "", xmlData, "FactorySum", "600", "300", False, False) End Function End Class
The following actions are taking place in this code: We first include DataConnection and InfoSoftGlobal namespace. DataConnection contains the connection parameters to connect to database. Next, we include FusionCharts.js JavaScript class to enable easy embedding of FusionCharts and call GetFactorySummaryChartHtml() method contained in code behind page. In GetFactorySummaryChartHtml() function, we then open a connection to database and retrieve the data as per the SQL passed. Thereafter, we generate the XML data document by iterating through the recordset and store it in xmlData variable. Finally, we render the chart using FusionCharts.RenderChart() method and pass xmlData as dataXML. When you now run the code, you'll get an output as under:
Converting the example to use dataURL method
Let's now convert this example to use dataURL method. As previously explained, in dataURL mode, you need two pages: Chart Container Page - The page which embeds the HTML code to render the chart. This page also tells the chart where to load the data from. We'll name this page as Default.aspx. Data Provider Page - This page provides the XML data to the chart. We'll name this page as PieData.aspx The pages in this example are contained in Download Package > Code > VB_NET > DB_dataURL folder.
Chart Container Page - Default.aspx
Default.aspx contains the following code (with code behind page) to render the chart:
<%@ Page Language="VB" AutoEventWireup="false" CodeFile="Default.aspx.vb" Inherits="DB_dataURL_Default" %> <HTML> <HEAD> <TITLE>FusionCharts - dataURL and Database Example </TITLE> <SCRIPT LANGUAGE="Javascript" SRC="../FusionCharts/FusionCharts.js"></SCRIPT> </HEAD> <body> <form id='form1' name='form1' method='post' runat="server"> <%=GetQuantityChartHtml()%> </form> </body> </HTML> Public Function GetQuantityChartHtml() As String 'In this example, we show how to connect FusionCharts to a database 'using dataURL method. In our other examples, we've used dataXML method 'where the XML is generated in the same page as chart. Here, the XML data 'for the chart would be generated in PieData.aspx. 'To illustrate how to pass additional data as querystring to dataURL, 'we've added an animate property, which will be passed to PieData.aspx. 'PieData.aspx would handle this animate property and then generate the 'XML accordingly. '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. 'Variable to contain dataURL 'Set DataURL with animation property to 1 'NOTE: It's necessary to encode the dataURL if you've added parameters to it Dim dataURL As String = Server.UrlEncode("PieData.aspx?animate=1") 'Create the chart - Pie 3D Chart with dataURL as strDataURL Return FusionCharts.RenderChart("../FusionCharts/Pie3D.swf", dataURL, "", "FactorySum", "600", "300", False, False) End Function
In the above code, we're: Including FusionCharts.js JavaScript class Create the dataURL string and store it in dataURL variable. We append a dummy propery animate to show how to pass parameters to dataURL. After building the dataURL, we encode it using Server.UrlEncode function. Finally, we render the chart using RenderChart() method and set dataURL variable as charts's dataURL.
Creating the data provider page PieData.aspx
PieData.aspx contains the following code to output XML Data:
Imports DataConnection Imports System.Text Partial Class DB_dataURL_PieData Inherits System.Web.UI.Page Private Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load 'This page generates the XML data for the Pie Chart contained in 'Default.aspx. '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. 'xmlData will be used to store the entire XML document generated Dim xmlData As New StringBuilder() 'Default.aspx has passed us a property animate. We request that. Dim animateChart As String animateChart = Request("animate") 'Set default value of 1 If ((Not (animateChart) Is Nothing) AndAlso (animateChart.Length = 0)) Then animateChart = "1" End If 'Create the recordset to retrieve data 'Generate the chart element xmlData.Append("<chart caption='Factory Output report' subCaption='By Quantity' pieSliceDepth='30' showBorder='1' formatNumberScale='0' numberSuffix=' Units' animation='" & animateChart & "'>") 'create recordset to get details for the factories Dim factoryQuery As String = "select a.FactoryId, a.FactoryName, sum(b.Quantity) as TotQ from .Factory_Master a, Factory_Output b where a.FactoryId=b.FactoryID group by a.FactoryId, a.FactoryName" Dim oRs As New DbConn(factoryQuery) 'Iterate through each factory While oRs.ReadData.Read() 'Generate <set name='..' value='..' /> xmlData.Append("<set label='" & oRs.ReadData("FactoryName").ToString() & "' value='" & oRs.ReadData("TotQ").ToString & "' />") End While oRs.ReadData.Close() 'Finally, close <chart> element xmlData = (xmlData + "</chart>") 'Set Proper output content-type Response.ContentType = "text/xml" 'Just write out the XML data 'NOTE THAT THIS PAGE DOESN'T CONTAIN ANY HTML TAG, WHATSOEVER Response.Write(xmlData) End Sub
In the above page: We first request the animate property which has been passed to it (from dataURL) We generate the data and store it in xmlData variable Finally, we write this data to output stream without any HTML tags. When you view this page, you'll get the same output as before.
Inside DataConnection Namespace
We have used DataConnection Namespace in the above code and in all subsequent Database examples. Using this class we establish connection to the MS Access database with ADO.NET component. Let's go through the lines of code inside this class:
Imports Microsoft.VisualBasic Imports System.Data.Odbc Imports System.Data Imports System.Web Imports System.Configuration Namespace DataConnection ''' <summary> ''' DataBase Connection Class. ''' </summary> Public Class DbConn Public connection As OdbcConnection Public ReadData As OdbcDataReader Public aCommand As OdbcCommand ''' <summary> ''' Data Connection and get Data Reader ''' </summary> ''' <param name="strQuery">SQL Query</param> Public Sub New(ByVal strQuery As String) Dim ConnectionString As String, connectionName As String ' MS Access DataBase Connection - Defined in Web.Config connectionName = "MSAccessConnection" '' SQL Server DataBase Connection - Defined in Web.Config '' connectionName = "SQLServerConnection"; ' Creating Connection string using web.config connection string ConnectionString = ConfigurationManager.ConnectionStrings(connectionName).ConnectionString Try ' Creating OdbcConnection Oject connection = New OdbcConnection() ' Setting Conection String connection.ConnectionString = ConnectionString ' Open Connection connection.Open() ' get reader GetReader(strQuery) Catch ex As Exception HttpContext.Current.Response.Write(ex.Message) End Try End Sub ''' <summary> ''' Create an instance dataReader ''' </summary> ''' <param name="strQuery">SQL Query</param> ''' <remarks>Return type object of OdbcDataReader</remarks> Public Sub GetReader(ByVal strQuery As String) ' Create a Command object aCommand = New OdbcCommand(strQuery, connection) ' Create data reader object using strQuery string ReadData = aCommand.ExecuteReader(CommandBehavior.CloseConnection) End Sub End Class End Namespace
What it does: Set up Connection as per the connection string defined in web.config file. <connectionStrings> <add name="MSAccessConnection" providerName="System.Data.Odbc" connectionString="Driver={Microsoft Access Driver (*.mdb)};Dbq=|DataDirectory|\FactoryDB.mdb"/> </connectionStrings> To change your connection to any other database server, you only need to setup web.config file. The code to connect to SQL Server Database is also given in comment form. To connect to SQL Server you have to activate the corresponding code. It accepts SQL Query, executes it and returns the result as ASP.NET DataReader object -ReadData.