MySqlConnection con = new MySqlConnection("Server = adres_serwera; port = 3306; database = nazwa_bazy; UID = login; password = hasło; CharSet = utf8");
con.Open();

string str = "DELETE FROM szefowie_ochrony WHERE ID = '" + textBox1.Text + "'";

MySqlCommand cmd = new MySqlCommand(str, con);
cmd.ExecuteNonQuery();
con.Close()