That was a looong journey to answer Linh’s question about user activity. The association between
books is many-to-many, it means there’s a join table named
books_users with both foreign keys from the
users table (
book_id). Here’s the table’s structure:
Every time a user starts reading a new book a new record to the
books_users table is added. The
created_at column has a precise date when the...