How to Build Your Own Clubhouse: Session #3

[booleanhunter]

Video

In this session, we finished with constructing the query to fetch rooms information:

The next series of exercises will help you get acquainted with the documentation and find answers

• Question 1: What is the default order in which rows are returned?
• Question 2: In many social media applications, new and latest information is usually shown first, at the start of the feed. And as you scroll and move down further, you see older information. Likewise, how can we ensure that the order of rows returned by the above query is always sorted by most recent room first?

Link to PostgreSQL documentation

[dandan682]

Answer to Question 1.

If sorting is not chosen, the rows will be returned in an unspecified order. The actual order in that case will depend on the scan and join plan types and the order on disk, but it must not be relied on. A particular output ordering can only be guaranteed if the sort step is explicitly chosen. The ORDER BY clause specifies the sort order.

Answer to Question 2.

ORDER BY rooms.date DESC