SQL> CREATE OR REPLACE TYPE personType AS OBJECT
2 (person_id VARCHAR2(10),
3 person_name VARCHAR2(30))
4 /
SQL> CREATE OR REPLACE TYPE courseType AS OBJECT
2 (course_id VARCHAR2(10),
3 course_name VARCHAR2(30))
4 /
Type created.
SQL>
SQL>
SQL>
SQL>
SQL> CREATE TABLE emp OF personType
2 (person_id NOT NULL,
3 PRIMARY KEY (person_id));
Table created.
SQL>
SQL> CREATE TABLE Course OF courseType
2 (course_id NOT NULL,
3 PRIMARY KEY (course_id));
Table created.
SQL>
SQL>
SQL>
SQL>
SQL> CREATE TABLE Enrolls_in
2 (emp REF personType,
3 course REF courseType);
Table created.
SQL>
SQL>
SQL>
SQL>
SQL>
SQL> drop table emp;
Table dropped.
SQL>
SQL> drop table Course;
Table dropped.
SQL>
SQL>
SQL>
SQL> drop table Enrolls_in;
Table dropped.
SQL>
SQL>
SQL>