Object Relational SQL Data Definition

1
Object Relational SQL - Data Definition

• New statement create type
• create type ADDRESS as OBJECT (STREET
  varchar2(50), HOUSE_NO number(5),
  CITY varchar2(30))
• create type PERSON as OBJECT (NAME
  varchar2(50), HOME_ADDRESS ADDRESS,
  BIRTH_DATE date, member
  function AGE (BIRTH in date) return
  number)
• Functions and procedures as attributes
• New statement create table of lttypegt
• create table FRIENDS of PERSON

2
Object Relational SQL Additional Features

• Construction of object types
• insert into FRIENDS values(Kaj A.
  Jørgensen, ADDRESS(Tranevej,48,Vo
  dskov), 1946-02-05)
• Definition of functions and procedures
• create type body PERSON as member function
  AGE(BIRTH in date) return number is begin
  return trunc(months_between(sysdate,BIRTH)/12)
  endend
• Function call example
• select avg(AGE(BIRTH_DATE)) from FRIENDS

3
Object Relational SQL Classification

• Classification, inheritance sub types under
  super types
• create type STUDENT as OBJECT under PERSON
  (EDUCATION varchar2(50), SEMESTER
  number)
• create type TEACHER as OBJECT under PERSON
  (DEPT_NAME varchar2(50),
  DEPT_ADDR ADDRESS)