CREATE TABLE compose(
	code_album varchar(4) NOT NULL,
	num_c	varchar(4) NOT NULL,
	position number(2) NOT NULL,
	CONSTRAINT pk_compose PRIMARY KEY (code_album,num_c),
	CONSTRAINT fk_c_album FOREIGN KEY (code_album) REFERENCES Album,
	CONSTRAINT fk_c_num   FOREIGN KEY (num_c) REFERENCES chanson
);