Recursive query of the parent class and subclass set in Oracle 11g

In an organization, it is often necessary to query all sub-classes under a department or all parent classes of a department. The recursive method is as follows:

1. query the subclass set

 
SelectA.*
FromOrganizations a startWithID= 97ConnectByNocycle prior A. ID=A. parentidOrder ByA. ID
 

2. query the parent class set

SelectA.*FromOrganizations a startWithID= 97
ConnectByNocycle prior A. parentid=A. IDOrder ByA. ID
 

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Note: During database table design, all departments are in the same table, and the Child parent node uses the parentid foreign key Association (during self-testing)

References:

A. http://docs.oracle.com/cd/B14117_01/server.101/b10759/queries003.htm#i2060615

B. http://docs.oracle.com/cd/B14117_01/server.101/b10759/pseudocolumns001.htm#i1009261