SELECT items.name AS item_name, categories.name AS category_name FROM items INNER JOIN item_categories ON item_categories.item_id = items.id INNER JOIN categories ON item_categories.category_id = categories.id WHERE items.name='arugula salad';
SELECT students.name AS student, classes.name AS class FROM students INNER JOIN enrollments ON enrollments.student_id = students.id INNER JOIN classes ON classes.id = enrollments.class_id;
SELECT students.name AS name, enrollments.grade AS grade FROM students INNER JOIN enrollments on enrollments.student_id = students.id;
SELECT students.name AS name, AVG(enrollments.grade) AS grade FROM students INNER JOIN enrollments on enrollments.student_id = students.id GROUP BY students.name;
SELECT students.name AS name, COUNT(enrollments.class_id) AS classes FROM students INNER JOIN enrollments on enrollments.student_id = students.id GROUP BY students.name;