Counting
You are interested in figuring out where the customers of eSymphony are ordering from. Specifically, you want to know from how many different U.S.A. orders are coming in.
To calculate this you will need to include a filter to your data before applying the correct group function. Let's start building this query!
Questo esercizio fa parte del corso
Introduction to Oracle SQL
Esercizio pratico interattivo
Prova a risolvere questo esercizio completando il codice di esempio.
-- Count the number of billing cities
SELECT ___(___)
FROM ___
-- Filter on rows where the billing country is the USA
WHERE ___