Retrieve Data from Multiple Tables Using LEFT JOIN

SELECT
  u.id AS user_id,
  u.username,
  p.title AS post_title,
  p.created_at AS post_date
FROM
  users u
LEFT JOIN
  posts p ON u.id = p.user_id
WHERE
  u.is_active = TRUE
ORDER BY
  u.id, p.created_at DESC;

How it works: This query uses a `LEFT JOIN` to combine data from the `users` and `posts` tables. It selects all active users and their associated posts. If a user has no posts, their details will still appear in the result set, with `NULL` values for the post columns, demonstrating the utility of a `LEFT JOIN` when you want to retain all records from the left table.