While insert the same data it will display already exist

In this blog we will know while inserting the same data it will display a message (Sorry! you can't take this). If we enter different data then it will display a message (You can take this) and data will be enter into the database.

 

 

Table creation

 

create table employee (eid int primary key identity,ename varchar(50),eaddress varchar(50))

 

 

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

 

<!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 runat="server">

    <title>Untitled Page</title>

</head>

<body>

    <form id="form1" runat="server">

    <div>

   

    </div>

    <asp:Button ID="Button1" runat="server" Text="Availability of name from the database"

        BackColor="#FF99FF" Font-Bold="True" Width="329px"

        onclick="Button1_Click" /><br />

    <asp:Label ID="Labelcheck"  Text="Ename" runat="server" BackColor="#FFFF99"

        Width="197px" ForeColor="#FF3300"></asp:Label>

        <asp:TextBox ID="txtUserName" runat="server" Width="197px"></asp:TextBox>

   

    <asp:RequiredFieldValidator ID="RequiredFieldValidator1" runat="server"

        ControlToValidate="txtUserName" ErrorMessage="*Name Required"></asp:RequiredFieldValidator><br />

       

       

        <asp:Label ID="Label1"  Text="Eaddress" runat="server" BackColor="#FFFF99"

        Width="197px" ForeColor="#FF3300"></asp:Label>

        <asp:TextBox ID="txtUserAddress" runat="server" Width="197px"></asp:TextBox>

   

    <asp:RequiredFieldValidator ID="RequiredFieldValidator2" runat="server"

        ControlToValidate="txtUserAddress" ErrorMessage="*Address Required"></asp:RequiredFieldValidator>

   

    <br />

    <asp:Label ID="lblMessage" runat="server" BackColor="#FF3300"

        ForeColor="Black"></asp:Label>

    </form>

</body>

</html>

using System;

using System.Collections;

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;

namespace Insert_data_ifnot_exits

{

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

    {

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

        SqlCommand com;

        string str = null;

       

 

        protected void Button1_Click(object sender, EventArgs e)

        {

            namecheck();

           

 

        }

        public void namecheck()

        {

            SqlConnection con = new SqlConnection(connStr);

            con.Open();

            str = "select count(*)from employee where ename='" + txtUserName.Text + "'";

            com = new SqlCommand(str, con);

            int count = Convert.ToInt32(com.ExecuteScalar());

            con.Close();

            if (count > 0)

            {

                lblMessage.Text = "Sorry! you can't take this username";

            }

            else

            {

                lblMessage.Text = "You can take this username";

                con.Open();

                str = "insert into employee(ename,eaddress) values('" + txtUserName.Text + "','" + txtUserAddress.Text + "')";

                com = new SqlCommand(str, con);

                com.ExecuteNonQuery();

                con.Close();

 

            }

          

        }

    }

}

 

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