MySQL introduced Window functions in their release of MySQL version 8.0. to target groups of rows without collapsing them. In this article, we wi

Use MySQL Window Functions to Get More out of Your Data

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2021-06-25 20:00:07

MySQL introduced Window functions in their release of MySQL version 8.0. to target groups of rows without collapsing them. In this article, we will explore example implementations of the most versatile window functions MySQL has to offer.

Window functions are an advanced feature offered by MySQL to improve the execution performance of queries. These functions act on a group of rows related to the targeted row called window frame. Unlike a GROUP BY clause, Window functions do not collapse the rows to a single row—preserving the details of each row instead. This new approach to querying data is invaluable in data analytics and business intelligence.

Aggregate functions are used to return a single scalar value from a set of rows. Some prominent aggregate functions available in MySQL are SUM, MIN, MAX, AVG, and COUNT. We can use these functions combined with the GROUP BY clause to get an aggregated value.

In contrast, window functions return a corresponding value for each of the targeted rows. These targeted rows, or the set of rows on which the window function operates, is called a window frame. Window functions use the OVER clause to define the window frame. A window function can include an aggregate function as a part of its SQL statement by using the OVER clause instead of GROUP BY.