SELECT * FROM `courses` WHERE show_on IN('all','courses')
SELECT * FROM courses_sections WHERE course_id IN(SELECT id FROM courses WHERE show_on IN ('all','courses'))

SELECT * FROM `cources_curriculum` WHERE section_id IN(SELECT id FROM courses_sections WHERE course_id IN(SELECT id FROM courses WHERE show_on IN ('all','courses')))

SELECT * FROM `curriculum_questions` WHERE curriculum_id IN(SELECT id FROM `cources_curriculum` WHERE section_id IN(SELECT id FROM courses_sections WHERE course_id IN(SELECT id FROM courses WHERE show_on IN ('all','courses'))))

SELECT * FROM `curriculum_questions_details` WHERE curriculum_questions_details.quetion_id IN( SELECT id FROM `curriculum_questions` WHERE curriculum_id IN(SELECT id FROM `cources_curriculum` WHERE section_id IN(SELECT id FROM courses_sections WHERE course_id IN(SELECT id FROM courses WHERE show_on IN ('all','courses')))))

SELECT category_id FROM `courses_categories` WHERE course_id IN(SELECT id FROM `courses` WHERE show_on IN('all','courses'))