A single DataSet can contain one or many DataTable objects.
You can define parent/child relationships between the DataTable objects contained in a DataSet.
<%@ Page Language="C#" %>
<%@ Import Namespace="System.Data" %>
<%@ Import Namespace="System.Data.SqlClient" %>
<%@ Import Namespace="System.Web.Configuration" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
void Page_Load()
{
if (!Page.IsPostBack)
BuildTree();
}
void BuildTree()
{
string connectionString = WebConfigurationManager.ConnectionStrings["Products"].ConnectionString;
SqlConnection con = new SqlConnection(connectionString);
SqlDataAdapter dadCategories = new SqlDataAdapter("SELECT Id,Name FROM ProductCategories", con);
SqlDataAdapter dadProducts = new SqlDataAdapter("SELECT Title,CategoryId FROM Products", con);
DataSet dstProducts = new DataSet();
using (con)
{
con.Open();
dadCategories.Fill(dstProducts, "Categories");
dadProducts.Fill(dstProducts, "Products");
}
dstProducts.Relations.Add("Children", dstProducts.Tables["Categories"].Columns["Id"], dstProducts.Tables["Products"].Columns["CategoryId"]);
foreach (DataRow categoryRow in dstProducts.Tables["Categories"].Rows)
{
string name = (string)categoryRow["Name"];
TreeNode catNode = new TreeNode(name);
TreeView1.Nodes.Add(catNode);
DataRow[] productRows = categoryRow.GetChildRows("Children");
foreach (DataRow productRow in productRows)
{
string title = (string)productRow["Title"];
TreeNode productNode = new TreeNode(title);
catNode.ChildNodes.Add(productNode);
}
}
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
<title>Show DataSet</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:TreeView
id="TreeView1"
Runat="server" />
</div>
</form>
</body>
</html>
File: Web.config
<configuration>
<connectionStrings>
<add name="Products"
connectionString="Data Source=.\SQLEXPRESS;
AttachDbFilename=|DataDirectory|MyDatabase.mdf;Integrated Security=True;User Instance=True" />
</connectionStrings>
</configuration>