SQL Tutorials

SQL Query to Remove Duplicate Records While Keeping Latest Entry

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🧹 SQL Query to Remove Duplicate Records While Keeping the Latest Entry Duplicate data is one of the most common problems in database management. In this tutorial, you’ll learn how to remove duplicate records while keeping only the latest entry — based on a timestamp or unique ID. This technique works in MySQL, SQL Server, … Read more

SQL Query to Calculate Running Total Without Window Functions

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⚡ SQL Query to Calculate Running Total Without Window Functions (Step-by-Step Example) Calculating a running total (cumulative sum) is a key task in data reporting, especially for business dashboards, financial reports, and time-based analytics. Modern databases offer SUM() OVER() window functions to handle this easily — but what if your system doesn’t support them? Don’t … Read more