Leetcode and HackerRank SQL

A set of Leetcode SQL questions is available here.

Following is the directory structure of this set:

├── Easy
│   ├── Actors who cooperated with Directors atleast three times.sql
│   ├── Ads performance.sql
│   ├── Article views.sql
│   ├── Average selling price.sql
│   ├── Big Countries.sql
│   ├── Biggest Single number.sql
│   ├── Classes more than 5 students.sql
│   ├── Combine two tables.sql
│   ├── Consecutive available seats.sql
│   ├── Create Session bar chart.sql
│   ├── Customer placing the largest number of orders .sql
│   ├── Customers who never order.sql
│   ├── Delete duplicate emails.sql
│   ├── Duplicate Emails.sql
│   ├── Employee Bonus.sql
│   ├── Employees earning more than their managers.sql
│   ├── Find Customer Refree.sql
│   ├── Find the team size.sql
│   ├── Friend Requests 1.sql
│   ├── Friendly Movies streamed list.sql
│   ├── Game Play Analysis 1.sql
│   ├── Game play analysis 2.sql
│   ├── Group sold products by the date.sql
│   ├── Immediate food delivery.sql
│   ├── List the products ordered in a period.sql
│   ├── Not Boring movies.sql
│   ├── Number of comments per post.sql
│   ├── Product Sales Analysis 1.sql
│   ├── Product Sales Analysis 2.sql
│   ├── Project Employees 1.sql
│   ├── Project Employees 2.sql
│   ├── Queries quality and percentage.sql
│   ├── Reformat department table.sql
│   ├── Replace employee id with unique identifier.sql
│   ├── Reported posts.sql
│   ├── Rising Temperature.sql
│   ├── Sales Analysis 1.sql
│   ├── Sales Analysis 2.sql
│   ├── Sales Analysis 3.sql
│   ├── Sales Person.sql
│   ├── Second highest salary.sql
│   ├── Shortest Distance.sql
│   ├── Students and Examinations.sql
│   ├── Students with invalid departments.sql
│   ├── Swap Salary.sql
│   ├── Top Travellers.sql
│   ├── Triangle Judgement.sql
│   ├── User Activity for past 30 days 2.sql
│   ├── User activity for past 30 days 1.sql
│   └── Weather type in each country.sql
├── Hard
│   ├── Average Salary.sql
│   ├── Cumulative Salary.sql
│   ├── Department top three salaries.sql
│   ├── Find median given frequency of numbers.sql
│   ├── Find the quiet students in the exam.sql
│   ├── Game Play Analysis 5.sql
│   ├── Human traffic of stadium.sql
│   ├── Market Analysis 2.sql
│   ├── Median Employee Salary.sql
│   ├── Number of transactions per visit.sql
│   ├── Report contiguous dates.sql
│   ├── Sales by day of the week.sql
│   ├── Students report by geography.sql
│   ├── Total sales amount by year.sql
│   ├── Tournament Winners.sql
│   ├── Trips and Users.sql
│   └── User purchase platform.sql
└── Medium
    ├── Active Businesses.sql
    ├── Active Users.sql
    ├── Activity Participants.sql
    ├── All people report to the given manager.sql
    ├── Apples & Oranges.sql
    ├── Article Views 2.sql
    ├── Calculate Salaries.sql
    ├── Capital Gain.sql
    ├── Consecutive Numbers.sql
    ├── Count student number in departments.sql
    ├── Countries you can safely invest in.sql
    ├── Customers who bought a, b but not c.sql
    ├── Customers who bought all products.sql
    ├── Department Highest Salary.sql
    ├── Evaluate Boolean Expressions.sql
    ├── Exchange Seats.sql
    ├── Find the start and end number of continuous ranges.sql
    ├── Friend Requests 2.sql
    ├── Game Play Analysis 3.sql
    ├── Game Play Analysis 4.sql
    ├── Get highest answer rate question.sql
    ├── Get the second most recent activity.sql
    ├── Highest grade for each student.sql
    ├── Immediate Food Delivery 2.sql
    ├── Investments in 2016.sql
    ├── Last person to fit in the elevator.sql
    ├── Managers with atleast 5 direct reports.sql
    ├── Market Analysis 1.sql
    ├── Monthly Transaction 2.sql
    ├── Monthly Transactions 1.sql
    ├── Movie Rating.sql
    ├── NPV Queries.sql
    ├── New users daily count.sql
    ├── Nth Highest salary.sql
    ├── Page Recommnedations.sql
    ├── Product Price at a given date.sql
    ├── Product Sales Analysis 3.sql
    ├── Project Employees 3.sql
    ├── Rank scores.sql
    ├── Rectangles Area.sql
    ├── Reported Posts 2.sql
    ├── Restaurant growth.sql
    ├── Running total for different genders.sql
    ├── Second degree follower.sql
    ├── Shortest distance in a plane.sql
    ├── Team scores in football match.sql
    ├── Tree Node.sql
    ├── Unpopular Books.sql
    └── Winning Candidate.sql

Another set of solved Leetcode questions is available on this blog.

HackerRank set is also available on the same blog here.