True MySQL interview question (19) -- Tiktok -- select the list of users who have logged in for two consecutive days every month

Check that there is continuous login every month 2 User list of days

There is a “ User login record form ”, Contains two fields ： user id、 date .

give the result as follows ：

# Inquire about 2021 Every month of the year , continuity 2 There is a list of logged in users every day .
SELECT DISTINCT 
  MONTH( date ) AS  month ,
   user id 
FROM
  (SELECT 
    *,
    lead ( date ) over (
      PARTITION BY  user id,
      MONTH( date ) 
  ORDER BY  date 
  ) AS  Next login date of this month  
  FROM
     User login record form  
  WHERE YEAR( date ) = 2021) a 
WHERE DATEDIFF(
     Next login date of this month ,
     date 
  ) = 1 
ORDER BY  month