Dataset Column Definition
The SqlDataAdapter Object allows us to populate DataTable in a DataSet. We can use Fill method in the SqlDataAdapter for populating data in a Dataset. The Dataset can contains more than one Table at a time.
The data inside Table is in the form of Rows and Columns . The DataRow class represents the actual data contained in a table. You use the DataRow and its properties and methods to retrieve, evaluate, and manipulate the data in a table. In some situations we have to find the column headers in a DataTable. There is a ColumnsCollection Object in the Datatable hold the column Definitions. The following ASP.NET Source Code shows how to find Column Definitions from a Datatable.
Default.aspx
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
<title>Untitled Page</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:Button ID="Button1" runat="server" Text="Button" onclick="Button1_Click" />
<br />
<asp:ListBox ID="ListBox1" runat="server"></asp:ListBox>
<br />
<asp:Label ID="Label1" runat="server" Text="Label"></asp:Label>
</div>
</form>
</body>
</html>
Full Source | C#
using System;
using System.Data ;
using System.Data.SqlClient ;
using System.Configuration;
public partial class _Default : System.Web.UI.Page
{
protected void Button1_Click(object sender, EventArgs e)
{
string connectionString = ConfigurationManager.ConnectionStrings["SQLDbConnection"].ToString();
SqlConnection connection = new SqlConnection(connectionString);
DataSet ds = new DataSet ();
string sql = "select * from publishers";
try
{
connection.Open();
SqlDataAdapter adapter = new SqlDataAdapter(sql,connection );
adapter.Fill(ds);
DataTable dt = ds.Tables[0];
foreach (DataColumn column in dt.Columns)
{
ListBox1.Items.Add(column.ColumnName);
}
connection.Close();
}
catch (Exception ex)
{
Label1.Text = "Error in execution " + ex.ToString();
}
}
}
Full Source | VB.NET
Imports System.Data
Imports System.Data.SqlClient
Imports System.Configuration
Partial Class _Default
Inherits System.Web.UI.Page
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
Dim connectionString As String
Dim connection As SqlConnection
Dim ds As New DataSet
Dim dt As DataTable
Dim column As DataColumn
connectionString = ConfigurationManager.ConnectionStrings("SQLDbConnection").ToString
connection = New SqlConnection(connectionString)
Dim sql As String = "select * from publishers"
Try
connection.Open()
Dim adapter As New SqlDataAdapter(sql, connection)
adapter.Fill(ds)
dt = ds.Tables(0)
For Each column In dt.Columns
ListBox1.Items.Add(column.ColumnName)
Next
connection.Close()
Catch ex As Exception
Label1.Text = "Error in execution " & ex.ToString
End Try
End Sub
End Class
Click the following links to see full source code
C# Source Code
VB.NET Source Code
Related Topics