text: drop table aspectratio cascade constraints
  /
  drop table studio cascade constraints
  /
  drop table rating cascade constraints
  /
  drop table dvd cascade constraints
  /
  drop table genre cascade constraints
  /
  drop table person cascade constraints
  /
  drop table dvd_genre cascade constraints
  /
  drop table dvd_actor cascade constraints
  /
  drop table dvd_director cascade constraints
  /
  drop table dvd_writer cascade constraints
  /
  
  create table aspectratio
  (
  
  	aspectratio_id number( 8 ),
  	name varchar2( 25 ) not null,
  	description varchar2( 300 ),
  	
  	Constraint aspectratio_id_PK Primary Key( aspectratio_id )
  
  )
  /
  create table studio
  (
  
  	studio_id number( 8 ),
  	name varchar2( 25 ) not null,
  	description varchar2( 300 ),
  
  	Constraint studio_id_PK Primary Key( studio_id ),
  
  )
  /
  create table rating
  (
  
  	rating_id number( 8 ),
  	name varchar2( 25 ) not null,
  	description varchar2( 300 ),
  
  	Constraint rating_id_PK Primary Key( rating_id )
  
  )
  /
  create table dvd
  (
  	dvd_id number( 8 ),
  	title varchar2( 50 ) not null,
  	runningtime number( 3 ),
  	releaseyear number( 4 ),
  	plotdescription varchar2( 300 ),
  	color varchar2( 25 ),
  	studio_id number( 8 ),
  	aspectratio_id number( 8 ),
  	rating_id number( 8 ),
  	
  	Constraint dvd_id_PK Primary Key( dvd_id ),
  	Constraint dvd_FK_studio_id Foreign Key ( studio_id ) References studio( studio_id ),
  	Constraint dvd_FK_aspectratio_id Foreign Key ( aspectratio_id ) References aspectratio( aspectratio_id ),
  	Constraint dvd_FK_rating_id Foreign Key ( rating_id ) References rating( rating_id )
  )
  /
  create table genre
  (
  
  	genre_id number( 8 ),
  	name varchar2( 25 ) not null,
  	description varchar2( 300 ),
  
  	Constraint genre_id_PK Primary Key( genre_id )
  
  )
  /
  create table person
  (
  
  	person_id number( 8 ),
  	firstname varchar2( 20 ) not null,
  	lastname varchar2( 20 ) not null,
  	
  	Constraint person_id_PK Primary Key( person_id )
  
  )
  /
  create table dvd_genre
  (
  
  	dvd_id number( 8 ),
  	genre_id number( 8 ),
  
  	Constraint dvd_genre_FK_dvd_id Foreign Key ( dvd_id ) References dvd( dvd_id ),
  	Constraint dvd_genre_FK_genre_id Foreign Key ( genre_id ) References genre( genre_id )
  
  )
  /
  create table dvd_actor
  (
  
  	dvd_id number( 8 ),
  	person_id number( 8 ),
  	character_firstname varchar2( 20 ),
  	character_lastname varchar2( 20 ),
  
  	Constraint dvd_actor_FK_dvd_id Foreign Key ( dvd_id ) References dvd( dvd_id ),
  	Constraint dvd_actor_FK_person_id Foreign Key ( person_id ) References person( person_id )
  
  )
  /
  create table dvd_director
  (
  
  	dvd_id number( 8 ),
  	person_id number( 8 ),
  
  	Constraint dvd_director_FK_dvd_id Foreign Key ( dvd_id ) References dvd( dvd_id ),
  	Constraint dvd_director_FK_person_id Foreign Key ( person_id ) References person( person_id )
  
  )
  /
  create table dvd_writer
  (
  
  	dvd_id number( 8 ),
  	person_id number( 8 ),
  
  	Constraint dvd_writer_FK_dvd_id Foreign Key ( dvd_id ) References dvd( dvd_id ),
  	Constraint dvd_writer_FK_person_id Foreign Key ( person_id ) References person( person_id )
  
  )
  /