🔥 Most Asked SQL Window Function Patterns (Real Business Problems) If you master these patterns, you can solve many real-world SQL interview problems. 👇 🔹 Find Top 5 Products by Revenue in Each Category → ROW_NUMBER() / RANK() + PARTITION BY 🔹 Calculate Running Sales Revenue Over Time → SUM() OVER(ORDER BY Date) 🔹 Find Customer’s First Purchase Date → MIN() OVER(PARTITION BY Customer) 🔹 Find Latest Transaction of Every Customer → ROW_NUMBER() + PARTITION BY 🔹 Calculate Month-over-Month Sales Growth → LAG() + Date Functions 🔹 Compare Employee Salary With Department Average → AVG() OVER(PARTITION BY Department) 🔹 Find Highest Revenue Product in Each Category → RANK() + PARTITION BY 🔹 Calculate Customer Lifetime Value (Total Spend) → SUM() OVER(PARTITION BY Customer) 🔹 Identify Repeat Customers After First Purchase → ROW_NUMBER() + Filtering Logic 🔹 Calculate 7-Day Moving Average of Sales → AVG() OVER(ORDER BY Date ROWS BETWEEN) 🔹 Find Longest User Activity Streak → ROW_NUMBER() + Gaps & Islands 🔹 Calculate Product Contribution to Total Revenue → SUM() OVER() + Percentage Calculation 🔹 Detect Customers With Declining Purchases → LAG() + Comparison Logic ❤️ React if you want more SQL interview patterns based on real company problems!
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