public bool checkDuplicateAccount(string username) { bool Successful = false; SqlConnection cnn = DBUtils.GetConnection(); try { string SQL = "select * from Account where username = @username"; if (cnn.State == ConnectionState.Closed) { cnn.Open(); } SqlCommand cmd = new SqlCommand(SQL, cnn); cmd.Parameters.AddWithValue("@username", username); Console.Write(cmd); SqlDataReader rdr = cmd.ExecuteReader(); if (rdr.HasRows) { Successful = true; } } catch (Exception e) { Console.WriteLine(e); throw; } finally { cnn.Close(); } return(Successful); }