SQL Partition overview

How to Partition an existing SQL Server Table

💡 SQL Interview / Real-Time Question: 👉 How do you delete duplicate rows from a table while keeping only one copy? Here’s the clean SQL solution 👇 ✅ Method 1: Using ROW_NUMBER() (Best & Recommended) (Works in SQL Server, PostgreSQL, Oracle, MySQL 8 ) WITH duplicates AS ( SELECT *, ROW_NUMBER() OVER ( PARTITION BY column1, column2, column3 ORDER BY id ) AS rn FROM table_name ) DELETE FROM duplicates WHERE rn > 1; 🎯 Explanation: - PARTITION BY → identifies duplicates - ROW_NUMBER() → assigns a