Recursive Queries

Recursive queries are queries which call themselves within their contents.

Example

WITH RECURSIVE rec_prereq(course_id, prereq_id) AS (
    SELECT course_ID, prereq_ID
    FROM prereq
UNION
    SELECT rec_prereq.course_ID, prereq.prereq_ID
    FROM rec_rereq INNER JOIN prereq 
    ON rec_prereq.prereq_ID = prereq.course_ID
)

SELECT *
FROM rec_prereq