diff --git a/README.md b/README.md index 7b506fe..3cdfd2f 100644 --- a/README.md +++ b/README.md @@ -1,5 +1,34 @@ # Sql1 1. Problem 1: Big Countries (https://leetcode.com/problems/big-countries/) +Solution: + +SELECT name, population, area +FROM World +WHERE area >= 3000000 +OR population >=25000000; + 2. Problem 2: Nth Highest Salary (https://leetcode.com/problems/nth-highest-salary/) +Solution: + +CREATE FUNCTION getNthHighestSalary(N INT) RETURNS INT +BEGIN + RETURN ( + with cte as(select id, salary, DENSE_RANK() + OVER (ORDER BY salary DESC) AS dns_rnk + FROM Employee) + + SELECT DISTINCT IFNULL(salary, null) + FROM cte + WHERE dns_rnk = N + + ); +END + 3. Problem 3: Delete Duplicate Emails (https://leetcode.com/problems/delete-duplicate-emails/) +Solution: + +DELETE P1 +FROM Person P1 +JOIN Person P2 +Where P1.email = P2.email AND P1.id > P2.id