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Databases Reporting with SQL Aggregate and Numeric Functions Counting Groups of Rows

What if I use ORDER BY?

First I just want to state that I totally understand how GROUP BY works. But still, I want to know clearly why when I used ORDER BY like this:

SELECT category, COUNT(*) AS product_count FROM products ORDER BY category;

the result came up this way:



Why only 1 row showed up? Where are the two other rows Clothing and Electronics? I did not use any query to leave those two categories out. This really baffled me. Please help!

1 Answer

ivana kantnerova
ivana kantnerova
15,673 Points

because there is no group by category, the aggregation function "count (*)" counts all rows of the table => the result has only one row .. it displays only the first category only because there is no other rows in results ... agregational function always returns only one value