Запись из TextBox по нажатии кнопки в базу данных SQL

private void button1_Click(object sender, EventArgs e)
        {
            string connectionString = @"Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=|DataDirectory|\bd.mdf;Integrated Security=True";
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
               
                //SqlCommand command = new SqlCommand("INSERT INTO datchik VALUES (@datchik, @data, @vremay_p, @vremay_v, @schet)", connection);
                SqlCommand command = new SqlCommand("INSERT INTO datchik (datchik,data,vremay_p,vremay_v,schet)" + "VALUES (@datchik,@data,@vremay_p,@vremay_v,@schet)", connection);
                command.Parameters.AddWithValue("@datchik",textBox1.Text);
                command.Parameters.AddWithValue("@data", maskedTextBox3.Text);
                command.Parameters.AddWithValue("@vremay_p", maskedTextBox1.Text);
                command.Parameters.AddWithValue("@vremay_v", maskedTextBox2.Text);
                command.Parameters.AddWithValue("@schet", textBox5.Text);
                command.Connection.Open();
                command.ExecuteNonQuery();
            }
        }

SqlCommand command = new SqlCommand("INSERT INTO datchik (datchik,data,vremay_p,vremay_v,schet) VALUES (@datchik,@data,@vremay_p,@vremay_v,@schet)", connection);

command.Connection.Open();

connection.Open();