var authResult = new DataTable();
            using (var sqlConnection = new SqlConnection(connectionString))
            {
                sqlConnection.Open();

                using (var sqlCommand = new SqlCommand("SELECT Password FROM Users WHERE Username = @user", sqlConnection))
                {
                    sqlCommand.Parameters.Add("@user", SqlDbType.VarChar).Value = user;

                    using (var sqlReader = sqlCommand.ExecuteReader())
                    {
                        authResult.Load(sqlReader);
                    }
                }

            }

            if (authResult.Rows.Count == 0) return;

            //Username did Exist!
            var dbPassword = Convert.ToString(authResult.Rows[0]["Password"]);
            if (string.CompareOrdinal(dbPassword, pass) == 0)
            {
                //ADD DATA HERE
            }