A SELECT aluno.codigo, disciplina.nome, matricula.ano, matricula.periodo, COALESCE(MAX(nota.nota), -1) FROM aluno INNER JOIN matricula ON aluno.id_aluno = matricula.id_aluno INNER JOIN disciplina ON disciplina.id_disciplina = matricula.id_disciplina LEFT OUTER JOIN nota ON nota.id_matricula = matricula.id_matricula GROUP BY aluno.codigo, disciplina.nome, matricula.ano, matricula.periodo;
B SELECT aluno.codigo, disciplina.nome, matricula.ano, matricula.periodo, CASE MAX(nota.nota) IS NOT NULL THEN MAX(nota.nota) ELSE -1 END CASE FROM aluno INNER JOIN matricula ON aluno.id_aluno = matricula.id_aluno INNER JOIN disciplina ON disciplina.id_disciplina = matricula.id_disciplina LEFT OUTER JOIN nota ON nota.id_matricula = matricula.id_matricula GROUP BY aluno.codigo, disciplina.nome, matricula.ano, matricula.periodo;
C SELECT aluno.codigo, disciplina.nome, matricula.ano, matricula.periodo, CASE IS_VALUE_NULL(MAX(nota.nota)) THEN MAX(nota.nota) ELSE -1 END FROM aluno INNER JOIN matricula ON aluno.id_aluno = matricula.id_aluno INNER JOIN disciplina ON disciplina.id_disciplina = matricula.id_disciplina LEFT OUTER JOIN nota ON nota.id_matricula = matricula.id_matricula GROUP BY aluno.codigo, disciplina.nome, matricula.ano, matricula.periodo;
D SELECT aluno.codigo, disciplina.nome, matricula.ano, matricula.periodo, COALLESCE(MAX(nota.nota), -1) FROM aluno INNER JOIN matricula ON aluno.id_aluno = matricula.id_aluno INNER JOIN disciplina ON disciplina.id_disciplina = matricula.id_disciplina LEFT OUTER JOIN nota ON nota.id_matricula = matricula.id_matricula GROUP BY aluno.codigo, disciplina.nome, matricula.ano, matricula.periodo;
E SELECT aluno.codigo, disciplina.nome, matricula.ano, matricula.periodo, IF_IS_NULL(MAX(nota.nota), -1) FROM aluno INNER JOIN matricula ON aluno.id_aluno = matricula.id_aluno INNER JOIN disciplina ON disciplina.id_disciplina = matricula.id_disciplina LEFT OUTER JOIN nota ON nota.id_matricula = matricula.id_matricula GROUP BY aluno.codigo, disciplina.nome, matricula.ano, matricula.periodo;