datagrids not updating in different tabpages with a button which is outside of the tabcontrol

private void button1_Click_1(object sender, EventArgs e)
{
   if (tabControl1.SelectedTab == tabPage1)
   {
      SqlConnection sconn = new SqlConnection();
      sconn.ConnectionString = "Data Source=.\\SQLEXPRESS;Integrated Security=SSPI;Initial Catalog=depom";
      sconn.open();
      SqlCommand ins = new SqlCommand();
      ins.Connection = sconn;
      ins.CommandText = "update .....";
      ins.Parameters.AddWithValue("....");
      ins.Parameters.AddWithValue("...");
      SqlCommand ons = new SqlCommand();
      ons.Connection = sconn;
      ons.CommandText = "insert into ......";
      ons.Parameters.AddWithValue(
         "@...",malzemeDataGridView.Rows[i].Cells["dataGridViewTextBoxColumn1"].Value.ToString());
      ons.Parameters.AddWithValue(
         "....", malzemeDataGridView.Rows[i].Cells["nadi"].Value.ToString());
 //......
      ins.ExecuteNonQuery();
      ons.ExecuteNonQuery();
      sconn.Close();
   }
   else if (tabControl1.SelectedTab == tabPage2)
   {
      SqlConnection sconna = new SqlConnection();
      sconna.ConnectionString = "Data Source=.\\SQLEXPRESS;Integrated Security=SSPI;Initial Catalog=depom";
      sconna.Open();
      SqlCommand ups = new SqlCommand();
      ups.Connection = sconna;
      ups.CommandText = "update ....";
      ups.Parameters.AddWithValue("...");
      ups.Parameters.AddWithValue("...");
      SqlCommand dps = new SqlCommand();
      dps.Connection = sconna;
      dps.CommandText = "...";
      dps.Parameters.AddWithValue("...");
      SqlCommand pons = new SqlCommand();
      pons.Connection = sconna;
      pons.CommandText = ".....";
      pons.Parameters.AddWithValue("....");
      pons.Parameters.AddWithValue("....");
      //.....
      pons.ExecuteNonQuery();
      ups.ExecuteNonQuery();
      dps.ExecuteNonQuery();
      sconna.Close();
   }
   else
   { 
      MessageBox.Show("try out");
   }
}

MessageBox.Show("tab page 1");

MessageBox.Show("tab page 2);