2.1.21b. Nested query example

Use of query result as comparator for other (outer) query

SELECT DISTINCT course
FROM dept WHERE course IN (

SELECT d.course
FROM dept AS d, faculty AS f, student AS s
WHERE d.ownfac=f.id AND s.owndept=d.id
AND f.name='Eng' AND s.year='3'

) OR course IN (

SELECT course
FROM dept
WHERE code LIKE 'COMS3%');