Query for check Duplicate data in Database.

Question

Hi all,
i am simply adding some data in to MsAccess database using Insert query.
now i want to do if i am inserting same data in Database again it should not add same data and give some error msg.
plz help me..

Satyapriya Nayak · Answer

Hi Sumit, Try this... Normal 0 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(); } } } } Thanks If this post helps you mark it as answer

Senthilkumar · Answer

Hi, Is that right way to do? two hits to database. First it checks the data exits or not through the query Second based on the selected results again sends to database for insert? Why you can't have the stored procedure to pass everything. If exists then throw error message, if not then insert and send the identity value.

Query for check Duplicate data in Database.

Answers (2)