SQL> CREATE TABLE Person
2 (id VARCHAR2(10) NOT NULL,
3 name VARCHAR2(20),
4 address VARCHAR2(35),
5 PRIMARY KEY (id));
SQL>
SQL>
SQL> CREATE TABLE emp
2 (id VARCHAR2(10) NOT NULL,
3 course VARCHAR2(10),
4 year VARCHAR2(4),
5 PRIMARY KEY (id),
6 FOREIGN KEY (id) REFERENCES Person (id) ON DELETE CASCADE);
Table created.
SQL>
SQL>
SQL>
SQL> CREATE TABLE Staff
2 (id VARCHAR2(10) NOT NULL,
3 department VARCHAR2(10),
4 room_no VARCHAR2(4),
5 PRIMARY KEY (id),
6 FOREIGN KEY (id) REFERENCES Person (id) ON DELETE CASCADE);
SQL>
SQL>
SQL> CREATE TABLE Tutor
2 (id VARCHAR2(10) NOT NULL,
3 no_hours NUMBER,
4 rate NUMBER,
5 PRIMARY KEY (id) ,
6 FOREIGN KEY (id) REFERENCES Person (id) ON DELETE CASCADE);
Table created.
SQL>
SQL>
SQL> drop table Person cascade constraints;
Table dropped.
SQL>
SQL>
SQL> drop table emp;
Table dropped.
SQL>
SQL> drop table Staff;
SQL>
SQL> drop table Tutor;
Table dropped.
SQL>