how to check username exist in database?

Question

Hi all how to check username exist in database. Thanks

Madhu K · Answer

Same is working for me. Take a Label in your aspx page. Debug the code using break points to check your problem. if (TextBox1.Text == reader[UserName].ToString()) { Response.Write(Username exists); break; } else { Label1.Text= Username does not exists; } }

Satyapriya Nayak · Answer

Many many thanks Madhu for your help.Now its working fine.

Satyapriya Nayak · Answer

Still problemiam attaching the code.

Madhu K · Answer

str = select UserName from Login where UserName='+TextBox1.Text +' ; The above statement enters while loop when it is true ie when there are records. So when there are no records while loop is not executed and hence you dont get any message in the loop. Change the statement to str = select UserName from Login; and use break in the loop so that once username exists it comes out of loop instead of checking all the records. if (TextBox1.Text == reader[UserName].ToString()) { Response.Write(Username exists); break; } else { Response.Write(Username doesnotexists); }

Satyapriya Nayak · Answer

Thanks Madhu  But in the below code if user is present it shows the Username exists but when user is not there it doesnot shows any messagewhats wrong in the program. con = new SqlConnection(connStr); con.Open(); str = select UserName from Login where UserName='+TextBox1.Text +' ; cmd = new SqlCommand(str con); SqlDataReader reader=cmd.ExecuteReader(); while (reader.Read()) { if (TextBox1.Text == reader[UserName].ToString()) { Response.Write(Username exists); } else { Response.Write(Username doesnotexists); } } con.Close(); reader.Close();

Madhu K · Answer

//SqlConnection.. SqlCommand SqlCmd1 = new SqlCommand(); SqlCmd1.CommandType = CommandType.Text; SqlCmd1.Connection = SqlCnn; SqlCmd1.CommandText = select username from users where ; SqlCnn.Open(); SqlDataReader Sqldr = SqlCmd1.ExecuteReader(); while (Sqldr.Read()) { //username is value to check.. if(username==Sqldr[username].ToString()) { Response.Write(Username exists); break; } } Sqldr.Close(); SqlCnn.Close();