DB Development Interview Question:

What is the family trees and connection by clause?

Submitted by: Administrator

On its face, the relational database management system would appear to be a very poor tool for representing and manipulating trees. This chapter is designed to accomplish the following things:
show you that a row in an SQL database can be thought of as an object
show you that a pointer from one object to another can be represented by storing an integer key in a regular database column
demonstrate the Oracle tree extensions (CONNECT BY … PRIOR)
show you how to work around the limitations of CONNECT BY with PL/SQL
The canonical example of trees in Oracle is the org chart.
create table corporate_slaves (
slave_id integer primary key,
supervisor_id references corporate_slaves,
name varchar(100)
);
insert into corporate_slaves values (1, NULL, ‘Big Boss Man');
insert into corporate_slaves values (2, 1, ‘VP Marketing');
insert into corporate_slaves values (3, 1, ‘VP Sales');
insert into corporate_slaves values (4, 3, ‘Joe Sales Guy');
insert into corporate_slaves values (5, 4, ‘Bill Sales Assistant');
insert into corporate_slaves values (6, 1, ‘VP Engineering');
insert into corporate_slaves values (7, 6, ‘Jane Nerd');
insert into corporate_slaves values (8, 6, ‘Bob Nerd');
Submitted by: Administrator