An Oracle query from a subnode to a parent node

Today, a person in the department asked me how to trace data from a subnode record to a parent node in Oracle. For example, there is a table:

Guid parentguid

1 0

2 1

3 1

4 2

5 2

6 5

7 5

8 7

We can find all the sub-nodes under the guid Based on the parentguid relationship.

If the guid of a subnode is 7, you need to find out its parent node, which is 7-> 5-> 2-> 1.

In fact, this is a very funny question. If you can find the child node from the parent node, then in turn, use the guid of the child node as the parentguid of the parent node.

The child node becomes the parent node.

Select guid from Test start with guid = 7 connect by prior parentguid = guid

You can find the relationship between 7-> 5-> 2-> 1.