In this blog we will know how to Compare Two columns values in database and show the output in a Gridview.

Table creation

Create two tables named as t1 and t2 having id column each on both the tables.

Table t1 Table t2

id id

1 3

2 4

3 5

4 6

Default.aspx code

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<title>Untitled Page</title>

</head>

<body>

<div>

<asp:GridView ID="GridView1" runat="server" ForeColor="#FF3300">

</asp:GridView>

<asp:Button ID="btnc_1to2" runat="server"

Text="compare column1's values with column2" onclick="btnc_1to2_Click"

Width="250px" /><br />

<asp:GridView ID="GridView2" runat="server" ForeColor="#663300">

</asp:GridView>

<asp:Button ID="btnc_2to1" runat="server"

Text="compare column2's values with column1" onclick="btnc_2to1_Click"

Width="250px" />

</div>

</form>

</body>

</html>

Default.aspx.cs code

using System;

using System.Configuration;

using System.Data;

using System.Linq;

using System.Web;

using System.Web.Security;

using System.Web.UI;

using System.Web.UI.HtmlControls;

using System.Web.UI.WebControls;

using System.Web.UI.WebControls.WebParts;

using System.Xml.Linq;

using System.Data.SqlClient;

public partial class _Default : System.Web.UI.Page

{

string strConnString = ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString;

string str;

SqlCommand com;

protected void btnc_1to2_Click(object sender, EventArgs e)

{

SqlConnection con = new SqlConnection(strConnString);

con.Open();

str = "select * from t1 except select * from t2";

com = new SqlCommand(str, con);

SqlDataReader reader = com.ExecuteReader();

GridView1.DataSource = reader;

GridView1.DataBind();

con.Close();

}

protected void btnc_2to1_Click(object sender, EventArgs e)

{

SqlConnection con = new SqlConnection(strConnString);

con.Open();

str = "select * from t2 except select * from t1";

com = new SqlCommand(str, con);

SqlDataReader reader = com.ExecuteReader();

GridView2.DataSource = reader;

GridView2.DataBind();

con.Close();

}

Output

Thanks for reading