LeetCode SQL 1661 | Average Time of Process per Machine | CASE WHEN & SUM

🚀 Welcome to the LeetCode SQL Easy to Hard Interview Series! In this video, we'll solve LeetCode SQL Problem 1661 - Average Time of Process per Machine. In this problem, we need to calculate the average time each machine takes to complete a process. We'll use CASE WHEN, SUM(), COUNT(), ROUND(), and GROUP BY to calculate the processing time between the start and end of each process. 📌 LeetCode Problem: LeetCode 1661 - Average Time of Process per Machine 🔗 Solve this problem yourself: https://leetcode.com/problems/average... 💡 Concepts Covered: ✔ CASE WHEN ✔ SUM() ✔ COUNT() ✔ ROUND() ✔ GROUP BY ✔ Aggregate Functions ✔ Calculating Time Difference ✔ Conditional Aggregation ✔ SQL Interview Questions ✔ Debugging SQL Queries ⏱ Timeline 00:00 Introduction 00:35 Understanding the Problem 01:10 Understanding the Activity Table 01:45 Understanding Start and End Records 02:20 Understanding the Example 02:55 Calculating Processing Time 03:25 Writing the First SQL Query 04:00 Using CASE WHEN 04:35 Calculating Start and End Time Difference 05:10 Grouping by Machine 05:45 Running the Query 06:15 Understanding the Wrong Answer 06:45 Debugging the Query 07:15 Correcting the Calculation 07:50 Using SUM() and COUNT() 08:20 Using ROUND() 08:45 Final Query Explanation 09:05 Accepted Solution 09:20 Final Result 🎯 What You'll Learn: • How to calculate the processing time between two events • How CASE WHEN can be used for conditional calculations • How to use SUM() with conditional logic • How COUNT(DISTINCT) can help calculate the number of processes • How ROUND() works in SQL • How GROUP BY works with aggregate functions • How to debug and correct a SQL query • How to solve SQL interview questions step by step 📚 Complete LeetCode SQL Playlist:    • LeetCode SQL Solutions | Easy to Hard | SQ...   👍 If this video helped you: ✅ Like the video ✅ Subscribe for more SQL interview questions ✅ Try solving the LeetCode problem yourself ✅ Comment your approach below 🔔 Follow the complete LeetCode SQL series from Easy to Hard! #leetcode #sql #casewhen #groupby #mysql #sqlinterview