分层SQL问题 [英] Hierarchical SQL question

问题描述

我有一个基本的实体树结构.该树最多可以有5个节点深，但可以有N个节点宽.我已将这种关系映射到类似于以下所示的表中:

I have a basic tree structure of entities. The tree can be a maximum of 5 nodes deep, but may be N nodes wide. I have mapped this relationship in table similar to what is shown below:

myID | myDescription | myParentID

我从一个已知的对象开始，这可以转换为具有起始的"myID".现在，我想获取所有子节点.有没有一种方法可以在一条语句中获得所有子节点?这需要包括我的孩子们的孩子，然后沿着树走下去.我正在使用Oracle SQL.

I am starting out with a known object, which could translate to having a starting "myID". Now I want to get all the child nodes. Is there a way of getting all the child nodes in one statement? This needs to include the children of my children, and going on down the tree. I am using Oracle SQL.

谢谢， 杰伊

推荐答案

SELECT  *
FROM    mytable
START WITH
        myid = :id
CONNECT BY
        myparentid = PRIOR myid

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