COMMIT

apples_oranges.sql

@@ -0,0 +1,4 @@
+with cte as (select sale_date, sold_num from sales where fruit = 'apples' order by sale_date),
+cte1 as (select sale_date, sold_num from sales where fruit = 'oranges' order by sale_date)
+select t.sale_date, t.sold_num - (select t1.sold_num from cte1 as t1 where t.sale_date
+= t1.sale_date) AS diff from cte as t;

top_travellers.sql

@@ -0,0 +1,2 @@
+select u.name, IFNULL(sum(r.distance),0) as travelled_distance from users u 
+LEFT JOIN rides r ON u.id = r.user_id GROUP BY r.user_id ORDER BY travelled_distance DESC, u.name;