SQL50

This repository contains my solutions for LeetCode SQL50 problems in MySQL, organized by topic and difficulty

Topics Covered

• Basic SELECT
• Basic JOINs
• Basic Aggregate Functions
• Sorting and Grouping
• Advanced SELECT and JOINs
• Subqueries
• Advanced String Functions / RegEx / Clause

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Basic SELECT

• 1757: Recyclable and Low Fat Products [solution]

• 584: Find Customer Referee [solution]

• 595: Big Countries [solution]

• 1148: Article Views I [solution]

• 1683: Invalid Tweets [solution]

Basic JOINs

• 1378: Replace Employee ID With The Unique Identifier [solution]

• 1068: Product Sales Analysis I [solution]

• 1581: Customer Who Visited but Did Not Make Any Transactions [solution]

• 197: Rising Temperature [solution]

• 1661: Average Time of Process per Machine [solution]

• 577: Employee Bonus [solution]

• 1280: Students and Examinations [solution]

• 570: Managers with at Least 5 Direct Reports [solution]

• 1934: Confirmation Rate [solution]

Basic Aggregate Functions

• 620: Not Boring Movies [solution]

• 1251: Average Selling Price [solution]

• 1075: Project Employees I [solution]

• 1633: Percentage of Users Attended a Contest [solution]

• 1211: Queries Quality and Percentage [solution]

• 1193: Monthly Transactions I [solution]

• 1174: Immediate Food Delivery II [solution]

• 550: Game Play Analysis IV [solution]

Sorting and Grouping

• 2356: Number of Unique Subjects Taught by Each Teacher [solution]

• 1141: User Activity for the Past 30 Days I [solution]

• 1070: Product Sales Analysis III [solution]

• 596: Product Sales Analysis III [solution]

• 1729: Find Followers Count [solution]

• 619: Biggest Single Number [solution]

• 1045: Customers Who Bought All Products [solution]

Advanced SELECTs and JOINs

• 1731: The Number of Employees Which Report to Each Employee [solution]

• 1789: Primary Department for Each Employee [solution]

• 610: Triangle Judgment [solution]

• 180: Consecutive Numbers [solution]

• 1164: Product Price at a Given Date [solution]

• 1204: Last Person to Fit in the Bus [solution]

• 1907: Count Salary Categories [solution]

Subqueries

• 1978: Employees Whose Manager Left the Company [solution]

• 626: Exchange Seats [solution]

• 1341: Movie Rating [solution]

• 1321: Restaurant Growth [solution]

• 602: Friend Requests II: Who Has the Most Friends [solution]

• 585: Investments in 2016 [solution]

• 185: Department Top Three Salaries [solution]

Advanced String Functions / Regex / Clause

• 1167: Fix Names in a Table [solution]

• 1527: Patients With a Condition [solution]

• 196: Delete Duplicate Emails [solution]

• 176: Second Highest Salary

  • Distinct [solution]
  • Dense Rank [solution]

• 1484: Group Sold Products By The Date [solution]

• 1484: Group Sold Products By The Date [solution]

• 1327: List the Products Ordered in a Period [solution]

• 1517: Find User With Valid E-Mails [solution]