CREATE TABLE vehicles OF carType;

Question

Given the following example of an object type in Oracle:
CREATE TYPE carType AS OBJECT (
regNo VARCHAR2 (8),
make VARCHAR2 (20),
model VARCHAR2 (20));

State the two ways:
(a) in which the ‘vehicles’ table can be viewed;
(b) to insert a record in the ‘vehicles’ table;
(c) to retrieve records of all Ford cars from the ‘vehicles’ table.

Answer 1

(a) The table can be viewed as:
- a single-column table in which each row is a carType object, allowing users to
perform object-oriented operations;
- a multi-column table in which each attribute of the object type carType, namely
regNo, make and model, occupies a column, allowing users to perform relational
operations.

(b) INSERT INTO vehicles VALUES (carType (‘T567SDF’, ‘Nissan’, ‘Primera’));
INSERT INTO vehicles VALUES (‘S123NPM’, ‘Ford’, ‘Escort’);

(c) SELECT VALUE(v) FROM vehicles v WHERE v.make = ‘Ford’;
SELECT * FROM vehicles WHERE make = ‘Ford’;