CREATE TABLE disciplinas (

disciplina varchar(6) not null, descricao varchar(80) not null, constraint disciplinas_pk primary key (disciplina)

); COMMENT ON TABLE disciplinas IS ‘Tabela que registra as disciplinas’;

INSERT INTO disciplinas VALUES(‘POR001’,‘PORTUGUÊS’); INSERT INTO disciplinas VALUES(‘MAT001’,‘MATEMÁTICA’); INSERT INTO disciplinas VALUES(‘HIS001’,‘HISTÓRIA’);

CREATE TABLE alunos (

matricula varchar(6) not null, nome varchar(80) not null, constraint alunos_pk primary key (matricula)

); COMMENT ON TABLE alunos IS ‘Tabela que registra os alunos’;

INSERT INTO alunos VALUES(‘202101’,‘JOÃO’); INSERT INTO alunos VALUES(‘202102’,‘JOSÉ’); INSERT INTO alunos VALUES(‘202103’,‘MARIA’); INSERT INTO alunos VALUES(‘202104’,‘JOAQUIM’);

CREATE TABLE turmas (

turma varchar(1) not null, disciplina varchar(6) not null, matricula varchar(6) not null, constraint disciplinas_fk foreign key (disciplina) references disciplinas (disciplina),

constraint alunos_fk foreign key (matricula)references alunos (matricula)

);

COMMENT ON TABLE turmas IS ‘Tabela que registra as disciplinas em que os alunos estão matriculados’; INSERT INTO turmas VALUES(‘A’,‘POR001’,‘202101’); INSERT INTO turmas VALUES(‘A’,‘POR001’,‘202102’); INSERT INTO turmas VALUES(‘B’,‘MAT001’,‘202101’); INSERT INTO turmas VALUES(‘B’,‘MAT001’,‘202103’); INSERT INTO turmas VALUES(‘C’,‘HIS001’,‘202102’); INSERT INTO turmas VALUES(‘C’,‘HIS001’,‘202104’);