check in database !!

Question

how can i authenticate that the given data doesn't exist in database !!!

Riddhi Valecha · Answer

Hi... What are you exactly trying to check?? Login Page - to check whether the user exists or not ?? Or some sort of data?? Please explain your question properly.

Jignesh Trivedi · Answer

hi you can also use IF Exist instead of count. string Name = 'Jignesh'; string query = IF EXISTS (SELECT 1 FROM Tables1 WHERE NAME = ' + Name + ') return 1 ELSE return 0; bool TableExists; using (SqlConnection connection = new SqlConnection(connectionString)) { using (SqlCommand command = new SqlCommand(query)) { command.CommandType = CommandType.Text; connection.Open(); command.Connection = connection; bool DataExists = (bool)(command.ExecuteScalar()); connection.Close(); } } hope this will help you.

Satyapriya Nayak · Answer

Untitled Page BackColor=#FF99FF Font-Bold=True Width=329px onclick=btn_check_Click /> Width=197px ForeColor=#FF3300> ControlToValidate=txtUserName ErrorMessage=*Name Required> ForeColor=Black> 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 Check_Data_dosenot_exist_database { public partial class _Default : System.Web.UI.Page { string connStr = ConfigurationManager.ConnectionStrings[ConnectionString].ConnectionString; SqlCommand com; string str; protected void btn_check_Click(object sender EventArgs e) { 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()); if (count > 0) { lblMessage.Text = username exist; } else { lblMessage.Text = username doesnot exist; } } } }