SELECT
course_aula_id aula_id,
e.student_id,
l.course_id,
e.enroll_id,
g.enroll_grade_id
FROM
cl_courses_x_aulas_link l
JOIN cl_students_enroll e ON
e.area_id = l.area_id AND e.ciclo_id = l.ciclo_id AND e.term_id = l.term_id AND e.section_id = l.section_id
JOIN cl_students_enrollment_grades g ON
g.course_id = l.course_id AND g.enroll_id = e.enroll_id
WHERE course_aula_id = 2156;