Question

I need to compose a SQL statement as follows:

I have a table with many items, each item having a category. In total there are 3 categories.

I need to select the DISTINCT categories and then order them by number of items within each category.

Would this be a good way? Or too slow?

SELECT DISTINCT category, count(*) AS counter
FROM item_descr
GROUP BY category
ORDER BY counter DESC

Answer 1

The DISTINCT is not needed since you are using GROUP BY category:

SELECT category, count(*) AS counter
FROM item_descr
GROUP BY category
ORDER BY counter DESC