Unique REF Cursor

From: <e.cunibil_at_gmail.com>
Date: 15 Jun 2006 19:18:45 -0700
Message-ID: <1150424324.938711.65990@f6g2000cwb.googlegroups.com>

Hello,

I am an IT Student and we learn using Oracle. I have a little problem with a REF I want to be unique. Let see my problem :

CREATE TYPE T_Group AS object (

        groupName VARCHAR2(30)
);

CREATE TYPE T_People AS object (

	num INTEGER,
	name VARCHAR2(30)

);

CREATE TYPE T_Student AS object (

	whoIs REF T_People,
	studentGroup REF T_Group

);

CREATE TABLE Group OF T_Group (

        CONSTRAINT pk_group PRIMARY KEY (groupName)
);

CREATE TABLE People OF T_People (

        CONSTRAINT pk_people PRIMARY KEY (num)
);

CREATE TABLE Student OF T_Student (

	CONSTRAINT un_whois_student UNIQUE(whoIs),
	CONSTRAINT notnull_group_student CHECK (studentGroup IS NOT NULL)

);

Unique constraint are forbidden on REF fields so do you know a way to make this field unique ?

Thanks a lot ! Received on Thu Jun 15 2006 - 21:18:45 CDT