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 identityename 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(enameeaddress) 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.