参考：DemoIntercept    
    /**

* 删除主表之前,删除子表数据,子表删除异常，事务回滚

*/

@Override

public String deleteBefore(AopContext ac) throws Exception {

String id = ac.record.getStr("id");

String sql = "delete from xxx_table where order_id = ?";

// Db.use(xx.DS_MAIN).update(sql, id);

System.out.println("级联删除数据:" + sql + id);

// 同理：级联删除、更新、备份、记日志...

return super.deleteBefore(ac);

}