Oracle finds all sub-categorical SQL statements

First build the table, org is the Department table, where OrgID indicates that the current department's Id,porgid is the ID of the parent department, the field type is an array type.

This table with a parent-child relationship uses the Oracle connect by statement to query up or down from a department:

Find all sub-departments from the Department ID 1 Department

SELECT * from org connect to prior orgid=porgid start with orgid=1;

Oracle finds all sub-categorical SQL statements