You where asked to help with the library system. It's simple SQL db with three tables User, Book and Borrow. Borrow table is journal. For each change in library - borrowing - you will have new row. E.g when you borrow a book, you will have new row in Borrow table with current timestamp. When you will return the book, you will have new row in Borrow table with current timestamp.
Below you can find schema for them:
User
| id | name |
|---|---|
| 1 | John Deer |
Book
| id | title | author | publish_year |
|---|---|---|---|
| 1 | First Book | Voodo Man | 2021 |
Borrow
| user_id | book_id | borrowed | timestamp |
|---|---|---|---|
| 1 | 2 | true | 2020-03-17 00:00:00.0 |