Welcome to my LeetCode SQL 50 journey!
This repository is a complete guide to mastering SQL for interviews. It includes:
- Optimal SQL Queries (Accepted on LeetCode)
- Line-by-line logic explanations
- Hand-drawn Visual Notes for quick revision
- 01. Select (5/5)
- 02. Basic Joins (9/9)
- 03. Basic Aggregate Functions (2/8)
- 04. Sorting and Grouping (0/7)
- 05. Advanced Select and Joins (0/7)
- 06. Subqueries (0/7)
- 07. Advanced String Functions (0/7)
| Day | Problem Solved | Link |
|---|---|---|
| Day 1 | 1757. Recyclable and Low Fat Products | View Notes |
| Day 2 | 584. Find Customer Referee | View Notes |
| Day 3 | 595. Big Countries | View Notes |
| Day 4 | 1148. Article Views I | View Notes |
| Day 5 | 1683. Invalid Tweets | View Notes |
| Day 6 | 1378. Replace Employee ID | View Notes |
| Day 7 | 1068. Product Sales Analysis I | View Notes |
| Day 8 | 1581. Customer Who Visited | View Notes |
| Day 9 | 197. Rising Temperature | View Notes |
| Day 10 | 1661. Average Time of Process | View Notes |
| Day 11 | 577. Employee Bonus | View Notes |
| Day 12 | 1280. Students and Examinations | View Notes |
| Day 13 | 570. Managers with 5 Reports | View Notes |
| Day 14 | 1934. Confirmation Rate | View Notes |
| Day 15 | 620. Not Boring Movies | View Notes |
| Day 16 | 1251. Average Selling Price | View Notes |
- 1757. Recyclable and Low Fat Products
- 584. Find Customer Referee
- 595. Big Countries
- 1148. Article Views I
- 1683. Invalid Tweets
- 1378. Replace Employee ID With The Unique Identifier
- 1068. Product Sales Analysis I
- 1581. Customer Who Visited but Did Not Make Any Transactions
- 197. Rising Temperature
- 1661. Average Time of Process per Machine
- 577. Employee Bonus
- 1280. Students and Examinations
- 570. Managers with at Least 5 Direct Reports
- 1934. Confirmation Rate
- 620. Not Boring Movies
- 1251. Average Selling Price
- 1075. Project Employees I
- 1633. Percentage of Users Attended a Contest
- 1211. Queries Quality and Percentage
- 1193. Monthly Transactions I
- 1174. Immediate Food Delivery II
- 550. Game Play Analysis IV
- 2356. Number of Unique Subjects Taught by Each Teacher
- 1141. User Activity for the Past 30 Days I
- 1070. Product Sales Analysis III
- 596. Classes With at Least 5 Students
- 1729. Find Followers Count
- 619. Biggest Single Number
- 1045. Customers Who Bought All Products
- 1731. The Number of Employees Which Report to Each Employee
- 1789. Primary Department for Each Employee
- 610. Triangle Judgement
- 180. Consecutive Numbers
- 1164. Product Price at a Given Date
- 1204. Last Person to Fit in the Bus
- 1907. Count Salary Categories
- 1978. Employees Whose Manager Left the Company
- 626. Exchange Seats
- 1341. Movie Rating
- 1321. Restaurant Growth
- 602. Friend Requests II: Who Has the Most Friends
- 585. Investments in 2016
- 185. Department Top Three Salaries
- 1667. Fix Names in a Table
- 1527. Patients With a Condition
- 196. Delete Duplicate Emails
- 176. Second Highest Salary
- 1484. Group Sold Products By The Date
- 1327. List the Products Ordered in a Period
- 1517. Find Users With Valid E-Mails