code: public void deleteServerGroup(int id) {
          try {
              sqlService.executeUpdate("DELETE FROM " + Constants.DB_TABLE_SERVER_GROUPS +
                                           " WHERE " + Constants.GENERIC_ID + " = " + id + ";");
  
              sqlService.executeUpdate("DELETE FROM " + Constants.DB_TABLE_SERVERS +
                                           " WHERE " + Constants.SERVER_REDIRECT_GROUP_ID + " = " + id);
          } catch (Exception e) {
              e.printStackTrace();
          }
      }
docs: Delete a server group by id
  
  @param id server group ID