SQL QA Collections

Welcome to the SQL QA Collection repository!

This repo gathers a variety of SQL questions and their solutions from multiple sources.

It serves as a resource for learning, practicing, and reviewing SQL concepts through Questions.

DataExpert.io

Question 01: Find Viewers with Multiple Article Views in a Day ➡️ Solution

Question 02: Check Test Answers ➡️ Solution

Question 03: Total Number of Births Per Year ➡️ Solution

Question 04: Cars with Above Average Engine Size ➡️ Solution

Question 05: Average Number of Births by Day of the Week ➡️ Solution

Question 06: Month with the Highest Total Births ➡️ Solution

Question 07: Customers with More Than 20 Orders ➡️ Solution

Question 08: Identifying Empty Departments ➡️ Solution

Question 09: Filtering Students in Active Clubs ➡️ Solution

Question 10: Identifying the Bank Robber ➡️ Solution

Question 11: Determining the Order of Succession ➡️ Solution

Question 12: Top Reviewed Customers per Product ➡️ Solution

Question 13: Find US Customers Who Rented and Streamed Videos in Early February ➡️ Solution

Question 14: Question: Analyze Yearly Profit Performance ➡️ Solution

Question 15: Select Rows With Maximum Revenue ➡️ Solution

Question 16: Salary Range Difference ➡️ Solution

Question 17: Find Product Prices ➡️ Solution

Question 18: Comparing State Fatal Collisions to the National Average ➡️ Solution

Question 19: Who are the top 10 authors by number of reviews ➡️ Solution

Question 20: Finding Highest Grade and Corresponding Course per Student ➡️ Solution

Question 21: Summarizing Foreign Competitors by Country with Total Summary ➡️ Solution

Question 22: Identifying Active Businesses Based on Event Occurrences ➡️ Solution

Question 23: Calculate 3-Day Rolling Average of Posts per User ➡️ Solution

Question 24: Top 2 Customers with Highest Sales Every Month ➡️ Solution

Question 25: Which states have high risk of fatal collisions involving Alcohol ➡️ Solution

Question 26 : Calculating Available Seats on Flights ➡️ Solution

Question 27: Most Popular Fuel System for Each Fuel Type ➡️ Solution

Question 28: Calculate Monthly Average Product Rating ➡️ Solution

Question 29: Transform workers_info Table to Exclude NULL Values ➡️ Solution

Question 30: Calculate Average Lead Time for Each Shipping Option ➡️ Solution

Question 31: Finding Actors by Favorite Movie Genre ➡️ Solution

Question 32: Analyze Engine Efficiency by Fuel Type ➡️ Solution

Question 33: Filtering Dance Contest Scores ➡️ Solution

Question 34: Identify Products Sold Exclusively in January 2024 ➡️ Solution

Question 35: Calculating Median Searches per User ➡️ Solution

Question 36: Determining Optimal Packaging for Christmas Gifts ➡️ Solution

Question 37: Countries and Their Preferences for Beer, Spirit, and Wine ➡️ Solution

Question 38: Most Frequently Purchased Sub-Category in Each Region ➡️ Solution

Question 39: Total Server Fleet Uptime in Full Days ➡️ Solution