yancya · August 8, 2019 07:37
diff --git a/order_by_case_when.rb b/order_by_case_when.rb
 ROOMS = ['a', 'b']
 rooms_order = ROOMS.map.with_index { |r, i| "WHEN '#{r}' THEN #{i} " }.join.yield_self { |s| "CASE room #{s} END"}
 Topic.where(room: ROOMS).order(rooms_order)
 #=> SELECT "topics".* FROM "topics" WHERE "topics"."room" IN ('a', 'b') ORDER BY CASE room WHEN 'a' THEN 0 WHEN 'b' THEN 1  END
	ROOMS = ['a', 'b']
	rooms_order = ROOMS.map.with_index { \|r, i\| "WHEN '#{r}' THEN #{i} " }.join.yield_self { \|s\| "CASE room #{s} END"}
	Topic.where(room: ROOMS).order(rooms_order)
	#=> SELECT "topics".* FROM "topics" WHERE "topics"."room" IN ('a', 'b') ORDER BY CASE room WHEN 'a' THEN 0 WHEN 'b' THEN 1 END