checking values weather it is present in database or not??

Question

hiiii i have designed one window application i want to add feature in it it should check data in database before deleting updating n inserting records

Satyapriya Nayak · Answer

Hi Hemant For windows app using Msaccess db Try this... using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Linq; using System.Text; using System.Windows.Forms; using System.Data.OleDb; namespace Insert_data_ifnot_exits_csharp { public partial class Form1 : Form { string ConnectionString = System.Configuration.ConfigurationSettings.AppSettings[dsn]; OleDbCommand com; OleDbDataAdapter oledbda; DataSet ds; string str; DataTable dt; public Form1() { InitializeComponent(); } private void btn_insert_Click(object sender EventArgs e) { namecheck(); } public void namecheck() { OleDbConnection con = new OleDbConnection(ConnectionString); con.Open(); str = select count(*)from employee where ename=' + txtUserName.Text + '; com = new OleDbCommand(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) values(' + txtUserName.Text + '); com = new OleDbCommand(str con); com.ExecuteNonQuery(); con.Close(); } } } } Thanks If this post helps you mark it as answer

Satyapriya Nayak · Answer

Hi Hemant Try this... Normal 0 Table 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