[SQL 문제 풀이] Queries Quality and Percentage (질의 품질 및 비율)

Can you solve this real interview question? Queries Quality and Percentage - Table: Queries +-------------+---------+ | Column Name | Type | +-------------+---------+ | query_name | varchar | | result | varchar | | position | int | | rating | int | +-------------+---------+ This table may have duplicate rows. This table contains information collected from some queries on a database. The position column has a value from 1 to 500. The rating column has a value from 1 to 5. Query with rating less than 3 is a poor query.   We define query quality as: > The average of the ratio between query rating and its position. We also define poor query percentage as: > The percentage of all queries with rating less than 3. Write a solution to find each query_name, the quality and poor_query_percentage. Both quality and poor_query_percentage should be rounded to 2 decimal places. Return the result table in any order. The result format is in the following example.   Example 1: Input: Queries table: +------------+-------------------+----------+--------+ | query_name | result | position | rating | +------------+-------------------+----------+--------+ | Dog | Golden Retriever | 1 | 5 | | Dog | German Shepherd | 2 | 5 | | Dog | Mule | 200 | 1 | | Cat | Shirazi | 5 | 2 | | Cat | Siamese | 3 | 3 | | Cat | Sphynx | 7 | 4 | +------------+-------------------+----------+--------+ Output: +------------+---------+-----------------------+ | query_name | quality | poor_query_percentage | +------------+---------+-----------------------+ | Dog | 2.50 | 33.33 | | Cat | 0.66 | 33.33 | +------------+---------+-----------------------+ Explanation: Dog queries quality is ((5 / 1) + (5 / 2) + (1 / 200)) / 3 = 2.50 Dog queries poor_ query_percentage is (1 / 3) * 100 = 33.33 Cat queries quality equals ((2 / 5) + (3 / 3) + (4 / 7)) / 3 = 0.66 Cat queries poor_ query_percentage is (1 / 3) * 100 = 33.33