Sometimes one query is not enough. Example: find all products whose price is above the average. First you compute the average price, then use it as a filter. Subqueries and CTEs break the work into steps and keep complex analytics readable.
Full content is available with a subscription.
Get full access to all courses on the platform for one year with a single payment.
▼
Unlike other platforms that charge per course, here you get everything for one price, and after one year of use there will be no automatic charge for the following year.