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();
}
}
}
}