Mock Sql 3 Completed

Market Analysis II .sql

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+with cte as (select order_date,item_brand , seller_id , rank() over ( partition by o.seller_id  order by o.order_date) as 'rnk'
+from orders o join items i on o.item_id=i.item_id )
+
+, cte2 as ( select * from cte where rnk=2)
+select user_id as 'seller_id', case
+when rnk=2 and  item_brand = favorite_brand then 'yes'
+else 'no'
+end as '2nd_item_fav_brand'
+ from users left join cte2 on cte2.seller_id=users.user_id 

Tournament Winners.sql

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+with cte1 as (select player_id,sum(total) as final_score 
+from (select first_player as player_id, first_score as total from Matches
+union all
+select second_player as player_id ,second_score as total from Matches) as cte
+group by player_id),
+
+cte2 as(select p.player_id, p.group_id , rank () over( partition by p.group_id order by ifnull(c.final_score,0) desc, p.player_id ) as rnk 
+from players p left join cte1 c 
+on p.player_id=c.player_id )
+
+select group_id, player_id from cte2 where rnk =1