Aggregates and GROUP BY
Aggregation collapses rows into summaries. WHERE filters before grouping and HAVING after — mixing them up is the classic bug.
- 6m
- Intermediate
Video by Becoming a Data Scientist · YouTube
Check your understanding
3 questions. Unlocks when you finish the video.
Overview
What this lesson covers
- Aggregate with count, sum, avg, min, and max
- Group correctly and know what must be in GROUP BY
- Filter groups with HAVING, rows with WHERE
This lesson sits in SQL Essentials, part of PostgreSQL for Developers. It assumes what came before it and leads directly into the next lesson in the module.
In this lesson you will:
- Aggregate with count, sum, avg, min, and max
- Group correctly and know what must be in GROUP BY
- Filter groups with HAVING, rows with WHERE
Resources
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