Insert and registration data not show in database table visual studio 2019

private void button2_Click(object sender, EventArgs e)
       {


           try
           {

               //taking data from the GUI

               string ID = textBox1.Text;
               string RegistrationNumber = textBox1.Text;
               string StudentName = textBox2.Text;
               string DateOfBirth = dateTimePicker1.Text;
               String Age = textBox3.Text;
               String Gender;
               if (radioButton1.Checked == true)
               {
                   Gender = "Male";
               }
               else
               {
                   Gender = "Female";
               }
               string ContactNumber = textBox4.Text;
               ;


               if (textBox1.Text == "" && textBox2.Text == "" && textBox3.Text == "" && textBox4.Text == "")

               {
                   MessageBox.Show("Complete the Missing Data");
               }
               else if (comboBox1.SelectedItem == null)
               {
                   MessageBox.Show("Click on the selected item after selecting a course");
               }
               else
               {
                   string course = (comboBox1.SelectedItem != null) ? comboBox1.SelectedItem.ToString() : "";
                   MessageBox.Show("Student Inserted Successfully!!");
                   string constr = (ConfigurationManager.ConnectionStrings["dbo.Table_1"] != null) ? ConfigurationManager.ConnectionStrings["dbo.Table_1"].ConnectionString : "";
                   connection = new SqlConnection("Data Source=.\\(localdb)\\MSSQLLocalDB;Initial Catalog=master;Integrated Security=True;Connect Timeout=30;Encrypt=False;TrustServerCertificate=False;ApplicationIntent=ReadWrite;MultiSubnetFailover=False");
                   using (SqlConnection con = new SqlConnection(constr))
                       con.ConnectionString = constr;

               }
               if (con.State == ConnectionState.Closed)
                   con.Open();

               SqlCommand com = new SqlCommand("INSERT INTO dbo.Table_1(ID, Registration Number, Student Name, Date of Birth, Age, Gender, Contact Number, Course Enrolled In) VALUES(@ID,@RegistrationNumber,@StudentName,@DateOfBirth,@Age,@Gender,@ContactNumber)", connection);

               com.CommandType = CommandType.Text;
               com.Connection = con;

               com.CommandText = "SELECT * FROM dbo.Table_1 WHERE ID = @ID;";
               com.Parameters.AddWithValue("@ID", textBox1.Text);
               com.Parameters.AddWithValue("@RegistrationNumber", textBox1.Text);
               com.Parameters.AddWithValue("@StudentName", textBox2.Text);
               com.Parameters.AddWithValue("@DateOfBirth", dateTimePicker1.Text);
               com.Parameters.AddWithValue("@Age", textBox3.Text);
               com.Parameters.AddWithValue("@Gender", Gender);
               com.Parameters.AddWithValue("@ContactNumber", textBox4.Text);

               com.ExecuteNonQuery();
               com.ExecuteReader();
               com.Dispose();


           }
           catch
           {
               MessageBox.Show("Error");
           }
           finally
           {
               con.Close();
           }




           }

private void button6_Click(object sender, EventArgs e)
{
    string ID = textBox1.Text;
    if (ID == null) ;
    if (textBox1.Text=="" || textBox2.Text=="" || textBox3.Text=="" || textBox4.Text=="")
    {
        MessageBox.Show("Please Enter Missing Details");
    }
    else
    {
        MessageBox.Show("Record Updated Successfully!!");
        string constr = (ConfigurationManager.ConnectionStrings["dbo.Table_1"] != null) ? ConfigurationManager.ConnectionStrings["dbo.Table_1"].ConnectionString : "";
        using (SqlConnection con = new SqlConnection(constr))
            con.ConnectionString = constr;
        if(con.State==ConnectionState.Closed)
        {
            con.Open();
        }


        String sql = "SELECT COUNT(*) AS [Count] FROM dbo.Table_1 WHERE ID =@ID";

        SqlCommand cmd = new SqlCommand(sql, con) ;
        cmd.Parameters.AddWithValue("@ID", ID);
        int Id;
        if (!int.TryParse(textBox1.Text, out Id))
        {
            // Report problem to your user
            return;
        }
        SqlDataReader sdr = cmd.ExecuteReader(CommandBehavior.CloseConnection);

        while (sdr.Read())


        {
            if (Convert.ToInt32(sdr["count"]) == 1)
            {
                button2.Enabled = false;
                button1.Enabled = true;
            }
            else
            {
                button2.Enabled = true;
                button1.Enabled = false;
             }


        }

        {

        }
    }
    con.Close();
}