LeetCode 619: Biggest Single Number
A SQL guide for finding the largest number that appears exactly once in a table.
Tag
Aggregation
13 notes
LeetCode 512: Game Play Analysis II
A clear explanation of finding the first device used by each player using SQL aggregation and a join.
LeetCode 511: Game Play Analysis I
A clear explanation of finding each player's first login date using SQL aggregation.
LeetCode 597: Friend Requests I: Overall Acceptance Rate
A clear SQL guide for computing the overall friend request acceptance rate with duplicate pairs counted once.
LeetCode 596: Classes With at Least 5 Students
A clear SQL guide for finding classes that have at least five students.
LeetCode 586: Customer Placing the Largest Number of Orders
A clear SQL guide for finding the customer who placed the most orders.
LeetCode 585: Investments in 2016
A clear SQL guide for summing 2016 investments for policies with repeated 2015 investment values and unique locations.
LeetCode 580: Count Student Number in Departments
A clear SQL guide for counting students in every department, including departments with zero students.
LeetCode 579: Find Cumulative Salary of an Employee
A clear SQL guide for computing each employee's 3-month cumulative salary while excluding their most recent month.
LeetCode 578: Get Highest Answer Rate Question
A clear SQL guide for finding the question with the highest answer rate from survey logs.
LeetCode 550: Game Play Analysis IV
A clear explanation of calculating the fraction of players who logged in again the day after their first login.
LeetCode 534: Game Play Analysis III
A clear explanation of computing cumulative games played per player and date using SQL window functions.
LeetCode 262: Trips and Users
A clear explanation of the Trips and Users SQL problem using joins, filtering, grouping, and conditional aggregation.