SQLaggregatesCOUNTSUM
What are COUNT, SUM, AVG, MIN, MAX in SQL? Aggregate functions for beginners
Aggregate functions are tools for "computing something across a group of rows". COUNT — how many rows, SUM — total, AVG — average, MIN/MAX — smallest and largest. Plain words: the difference between COUNT(*) and COUNT(column), how NULL affects aggregates, common scenarios, and pitfalls.
1 min de lectureSQL · aggregates · COUNT · SUM · tutorial
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These are the five most basic aggregate functions. They answer "how many", "how much in total", "average", "smallest", "largest" by collapsing a group of rows into a single number.
This article is currently in Russian. The full English translation is on the way.