如何创建 MySQL 分层递归查询？ - How to create a MySQL hierarchical recursive query?

问题：

I have a MySQL table which is as follows:我有一个 MySQL 表，如下所示：

Now, I want to have a single MySQL query to which I simply supply the id [for instance say id=19 ] then I should get all its child ids [ie result should have ids '20,21,22']....现在，我想要一个 MySQL 查询，我只需提供 id [例如说id=19 ] 然后我应该得到它的所有子 ID [即结果应该有 ids '20,21,22'] ... .

The hierarchy of the children is not known;孩子的等级是未知的； it can vary....它可以变化....

I know how to do it using a for loop... but how to achieve the same using a single MySQL query?我知道如何使用for循环来实现……但是如何使用单个 MySQL 查询来实现相同的目标？

---

解决方案：

参考一： http://stackoom.com/question/1Mp2O
参考二： How to create a MySQL hierarchical recursive query?