ror_coding

기존 코드도 좋지만, window function의 연산 범위를 잘 익혀야 한다! Question You are the restaurant owner and you want to analyze a possible expansion (there will be at least one customer every day).Compute the moving average of how much the customer paid in a seven days window (i.e., current day + 6 days before). average_amount should be rounded to two decimal places.Return the result table ordered by visited_on in ..

문제를 잘 읽자!!! subquery를 잘 활용하자..! Question Write a solution to:Find the name of the user who has rated the greatest number of movies. In case of a tie, return the lexicographically smaller user name.Find the movie name with the highest average rating in February 2020. In case of a tie, return the lexicographically smaller movie name.The result format is in the following example. Code select name a..

limit 1 offset 1; Question Write a solution to find the second highest distinct salary from the Employee table. If there is no second highest salary, return null (return None in Pandas).The result format is in the following example. Table: Employee +-------------+------+ | Column Name | Type | +-------------+------+ | id | int | | salary | int | +-------------+------+ id is the ..