Oracle and Object-Oriented SQL Oracle specific SQL commands

User-defined types CREATE TYPE source AS OBJECT ( name VARCHAR2(30), ra FLOAT, dec FLOAT ) NOT FINAL; /

Inheritance CREATE TYPE bsource UNDER source ( bmag NUMBER(5, 2) ) NOT FINAL; /

Instantiating a type An object table is a table with a single column of a user-defined type CREATE TABLE sources OF source; INSERT INTO sources VALUES ( rsource( 'R2D2', 4.3, -22.9, 21.2 ) );

Accessing types SELECT VALUE(*) FROM sources; retrieves constructors from “sources” CREATE VIEW sources$v OF source; an object view with objects of type “source” CREATE VIEW bsources$v OF bsource UNDER sources$v; an object view with objects of type “bsource” which, at the same time, makes those objects available from the “sources$v” view

References CREATE TABLE mysources ( petsource VARCHAR2(170), bestars REF source );

Methods Include in the TYPE definition: MEMBER FUNCTION lon() RETURN NUMBER CREATE TYPE BODY source AS MEMBER FUNCTION lon () RETURN NUMBER ISBEGIN /* left as an exercise */ RETURN lon; END; END;

Varying Arrays Fixed maximum size Fixed order CREATE TYPE intarray AS VARRAY(20) OF INTEGER; /

Nested tables Unlimited maximum size Random order CREATE TYPE intarray AS TABLE OF INTEGER; CREATE TABLE demo ( name VARCHAR2(37), v intarray ) NESTED TABLE v STORE AS vtable;

Command-line usage - start script named script.sql edit – edit the buffer describe – gives definition of datastructures spool – write results to file !command – run unix command in a shell ! – spawn a unix shell

GUI access oemapp worksheet oemapp console (requires SELECT ANY DICTIONARY privilige) Follow the built-in quick tours for an overview of database concepts and functions. Use the ‘Show SQL’ button to see what the equivalent SQL query is for a GUI operation

Python Python “class” ~ Oracle “type” Python DB API for direct access DBObject for ASTRO-WISE access from astro.database.DBMain import DBObject, persistent class Source(DBObject): name = persistent(‘The name’, str, ‘Nameless’) ra = persistent(‘R.A.’, float, 0.0) dec = persistent(‘Declination’, float, 0.0) The class is mapped to a “TYPE”, a “TABLE” and a “VIEW”!