Create recursive.sql

Author: erjan

pgexercises/recursive.sql

@@ -0,0 +1,47 @@
+with recursive recommenders(recommender) as (
+	select recommendedby from cd.members where memid = 27
+	union all
+	select mems.recommendedby
+		from recommenders recs
+		inner join cd.members mems
+			on mems.memid = recs.recommender
+)
+select recs.recommender, mems.firstname, mems.surname
+	from recommenders recs
+	inner join cd.members mems
+		on recs.recommender = mems.memid
+order by memid desc 
+
+
+
+with recursive recommendeds(memid) as (
+	select memid from cd.members where recommendedby = 1
+	union all
+	select mems.memid
+		from recommendeds recs
+		inner join cd.members mems
+			on mems.recommendedby = recs.memid
+)
+select recs.memid, mems.firstname, mems.surname
+	from recommendeds recs
+	inner join cd.members mems
+		on recs.memid = mems.memid
+order by memid          
+
+
+
+with recursive recommenders(recommender, member) as (
+	select recommendedby, memid
+		from cd.members
+	union all
+	select mems.recommendedby, recs.member
+		from recommenders recs
+		inner join cd.members mems
+			on mems.memid = recs.recommender
+)
+select recs.member member, recs.recommender, mems.firstname, mems.surname
+	from recommenders recs
+	inner join cd.members mems		
+		on recs.recommender = mems.memid
+	where recs.member = 22 or recs.member = 12
+order by recs.member asc, recs.recommender desc