Sampling of people who bought a product on a specific date sql?

Question

SQL

You have 3 tables:
users - users
purchases - purchases
skus - products Use
these tables to output the answers to the questions:
How many people bought the product with sku.id = 5 on October 10?
The query result must return a single digit.
How many people from Moscow bought phones in September and October?
The query result must return a format table.
month
people
september
n
october
m

n, m – number of people who bought phones in integer format.

Important to remember:
Not all people in the users table have made purchases.
In the users and purchases tables, the data is only for 2021.

Answer 1

SELECT COUNT(user_id) FROM purchases
WHERE user_id > 0 AND sku_id = 5 AND created_at = “10-10-2021”
this should seem to work for 1 question, but from 2 even xs