Watch 10 video solutions for Grand Slam Titles, a medium level problem involving Database. This walkthrough by NeetCode has 427,716 views views. Want to try solving it yourself? Practice on FleetCode or read the detailed text solution.
Table: Players
+----------------+---------+ | Column Name | Type | +----------------+---------+ | player_id | int | | player_name | varchar | +----------------+---------+ player_id is the primary key (column with unique values) for this table. Each row in this table contains the name and the ID of a tennis player.
Table: Championships
+---------------+---------+ | Column Name | Type | +---------------+---------+ | year | int | | Wimbledon | int | | Fr_open | int | | US_open | int | | Au_open | int | +---------------+---------+ year is the primary key (column with unique values) for this table. Each row of this table contains the IDs of the players who won one each tennis tournament of the grand slam.
Write a solution to report the number of grand slam tournaments won by each player. Do not include the players who did not win any tournament.
Return the result table in any order.
The result format is in the following example.
Example 1:
Input: Players table: +-----------+-------------+ | player_id | player_name | +-----------+-------------+ | 1 | Nadal | | 2 | Federer | | 3 | Novak | +-----------+-------------+ Championships table: +------+-----------+---------+---------+---------+ | year | Wimbledon | Fr_open | US_open | Au_open | +------+-----------+---------+---------+---------+ | 2018 | 1 | 1 | 1 | 1 | | 2019 | 1 | 1 | 2 | 2 | | 2020 | 2 | 1 | 2 | 2 | +------+-----------+---------+---------+---------+ Output: +-----------+-------------+-------------------+ | player_id | player_name | grand_slams_count | +-----------+-------------+-------------------+ | 2 | Federer | 5 | | 1 | Nadal | 7 | +-----------+-------------+-------------------+ Explanation: Player 1 (Nadal) won 7 titles: Wimbledon (2018, 2019), Fr_open (2018, 2019, 2020), US_open (2018), and Au_open (2018). Player 2 (Federer) won 5 titles: Wimbledon (2020), US_open (2019, 2020), and Au_open (2019, 2020). Player 3 (Novak) did not win anything, we did not include them in the result table.