Database Problems
94 Database LeetCode problems · Solve with AI-powered hints & step-by-step explanations.
Learn the patterns behind these problems with our SQL interview questions.
All Database problems
175 Combine Two Tables Easy176 Second Highest Salary Medium177 Nth Highest Salary Medium178 Rank Scores Medium180 Consecutive Numbers Medium181 Employees Earning More Than Their Managers Easy182 Duplicate Emails Easy183 Customers Who Never Order Easy184 Department Highest Salary Medium185 Department Top Three Salaries Hard196 Delete Duplicate Emails Easy197 Rising Temperature Easy262 Trips and Users Hard511 Game Play Analysis I Easy550 Game Play Analysis IV Medium570 Managers with at Least 5 Direct Reports Medium577 Employee Bonus Easy584 Find Customer Referee Easy585 Investments in 2016 Medium586 Customer Placing the Largest Number of Orders Easy595 Big Countries Easy596 Classes With at Least 5 Students Easy601 Human Traffic of Stadium Hard602 Friend Requests II: Who Has the Most Friends Medium607 Sales Person Easy608 Tree Node Medium610 Triangle Judgement Easy619 Biggest Single Number Easy620 Not Boring Movies Easy626 Exchange Seats Medium627 Swap Salary Easy1045 Customers Who Bought All Products Medium1050 Actors and Directors Who Cooperated At Least Three Times Easy1068 Product Sales Analysis I Easy1070 Product Sales Analysis III Medium1075 Project Employees I Easy1084 Sales Analysis III Easy1141 User Activity for the Past 30 Days I Easy1148 Article Views I Easy1158 Market Analysis I Medium1164 Product Price at a Given Date Medium1174 Immediate Food Delivery II Medium1179 Reformat Department Table Easy1193 Monthly Transactions I Medium1204 Last Person to Fit in the Bus Medium1211 Queries Quality and Percentage Easy1251 Average Selling Price Easy1280 Students and Examinations Easy1321 Restaurant Growth Medium1327 List the Products Ordered in a Period Easy1341 Movie Rating Medium1378 Replace Employee ID With The Unique Identifier Easy1393 Capital Gain/Loss Medium1407 Top Travellers Easy1484 Group Sold Products By The Date Easy1517 Find Users With Valid E-Mails Easy1527 Patients With a Condition Easy1581 Customer Who Visited but Did Not Make Any Transactions Easy1587 Bank Account Summary II Easy1633 Percentage of Users Attended a Contest Easy1661 Average Time of Process per Machine Easy1667 Fix Names in a Table Easy1683 Invalid Tweets Easy1693 Daily Leads and Partners Easy1729 Find Followers Count Easy1731 The Number of Employees Which Report to Each Employee Easy1741 Find Total Time Spent by Each Employee Easy1757 Recyclable and Low Fat Products Easy1789 Primary Department for Each Employee Easy1795 Rearrange Products Table Easy1873 Calculate Special Bonus Easy1890 The Latest Login in 2020 Easy1907 Count Salary Categories Medium1934 Confirmation Rate Medium1965 Employees With Missing Information Easy1978 Employees Whose Manager Left the Company Easy2356 Number of Unique Subjects Taught by Each Teacher Easy3220 Odd and Even Transactions Medium3374 First Letter Capitalization II Hard3421 Find Students Who Improved Medium3436 Find Valid Emails Easy3451 Find Invalid IP Addresses Hard3465 Find Products with Valid Serial Numbers Easy3475 DNA Pattern Recognition Medium3482 Analyze Organization Hierarchy Hard3497 Analyze Subscription Conversion Medium3521 Find Product Recommendation Pairs Medium3554 Find Category Recommendation Pairs Hard3564 Seasonal Sales Analysis Medium3570 Find Books with No Available Copies Easy3580 Find Consistently Improving Employees Medium3586 Find COVID Recovery Patients Medium3601 Find Drivers with Improved Fuel Efficiency Medium3611 Find Overbooked Employees Medium