Aggregations, GROUP BY & The HAVING Clause

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Aggregate data across business categories using COUNT, SUM, AVG, and master filtering aggregated rows with HAVING.

WHERE vs. HAVING: The Critical Difference

WHERE: Filters individual raw rows before any grouping or aggregation takes place.

HAVING: Filters grouped summary rows after the aggregation function has computed.

Filtering Groups with HAVING

Try It Yourself »

SELECT 
    Category,
    COUNT(*) AS ProductCount,
    AVG(Price) AS AvgPrice
FROM Products
WHERE InStock = 1                -- Filters raw rows
GROUP BY Category
HAVING COUNT(*) >= 5             -- Filters aggregated groups
   AND AVG(Price) < 100.00;

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Test Yourself With Exercise

+15 XP

Why can you not use an aggregate function like SUM(Total) > 1000 inside a standard WHERE clause?

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