멘토링 짝꿍 리스트 (solvesql) & 1148. Article Views I ,1683. Invalid Tweets(leetcode)

멘토링 짝꿍 리스트

https://solvesql.com/problems/mentor-mentee-list/

SELECT
  A.employee_id AS mentee_id,
  A.name AS mentee_name,
  B.employee_id AS mentor_id,
  B.name AS mentor_name
FROM
  employees A
  CROSS join employees B
WHERE
  A.join_date BETWEEN '2021-09-01' and '2021-12-31'
  AND B.join_date <= '2019.12.31'
  AND A.department != B.department
ORDER BY
  mentee_id,
  mentor_id

1148. Article Views I

https://leetcode.com/problems/article-views-i/description/?envType=study-plan-v2&envId=top-sql-50

SELECT DISTINCT author_id AS id
FROM views
WHERE author_id = viewer_id
ORDER BY id

1683. Invalid Tweets

https://leetcode.com/problems/invalid-tweets/description/?envType=study-plan-v2&envId=top-sql-50

SELECT tweet_id
FROM tweets
WHERE length(content) > 15