6.20 Leetcode 다시풀기 176,178,1050,1068,1069

176. Second Highest Salary

SELECT MAX(salary) AS SecondHighestSalary 
FROM Employee
WHERE salary < (SELECT MAX(salary) FROM Employee)

- 테스트 케이스를 맞추기 위한 풀이 

178. Rank Scores

MS로 하니까 된다! WINDOW라서 그런가봐 

SELECT score, DENSE_RANK() OVER (ORDER BY score DESC)rank 
FROM Scores 
ORDER BY rank

SELECT actor_id,director_id
FROM ActorDirector
GROUP BY actor_id,director_id 
HAVING COUNT(*)>=3

1068. Product Sales Analysis I

SELECT p.product_name
      ,s.year
      ,s.price
FROM Sales s
    JOIN Product p ON p.product_id=s.product_id

1069. Product Sales Analysis II

SELECT p.product_id
      ,SUM(s.quantity) as total_quantity
FROM Sales s
    JOIN Product p ON p.product_id=s.product_id
GROUP BY p.product_id