Re: Flamewar object databases vs. relational databases (was: Unknown SQL)

> Could you please provide samples for insert and select statements?
> Thanks!

Sure.

CREATE TABLE cities (name text,population int,altitude int); CREATE TABLE capitals (state char(2)) INHERITS (cities);

Insert a city (not a state capital):
INSERT INTO cities VALUES ('Provo', 350000, 4500);

Insert a state capital:
INSERT INTO capitals ('Salt Lake City', 500000, 5000, 'UT');

Select all cities:
SELECT * FROM cities;

| name           | population | altitude
| Provo          | 350000     | 4500
| Salt Lake City | 500000     | 5000

Select all captials:
SELECT * FROM capitals;

| name           | population | altitude | state
| Salt Lake City | 500000     | 5000     | UT

Select only cities:
SELECT * FROM ONLY cities;

| name           | population | altitude
| Provo          | 350000     | 4500

> Lee, someone, whoever:
> Does this conform to relational theories?
> Is there a common standard for select statements?

This is a non-standard extension to SQL. It actually supports multiple inheritance. SQL99 supports this type single inheritance but uses a different syntax.

Adam Ruth Received on Sat Jul 21 2001 - 18:29:42 CDT