| TABLE | customers | customer | The customer for the library | |
| id | AUTOINCREMENT | PK | Auto-generated id | |
| first | TEXT | NOT NULL | Customers’ first name | |
| last | TEXT | NOT NULL, INDEX | Customers’ last name | |
| ABSTRACT TABLE | media | media | The contents of the library | |
| id | AUTOINCREMENT | PK | Auto-generated id | |
| title | TEXT | The title of the media | ||
| author | TEXT | The author | ||
| published | DATE | Publication date | ||
| TABLE (media) | books | book | The books in the library | |
| pages | INTEGER | 100 | ||
| borrowed_by | FK customers(borrowed_books) | NULL | Who borrowed the media | |
| TABLE (media) | dvds | dvd | The dvds in the library | |
| region | INTEGER | 1 | ||
| borrowed_by | FK customers(borrowed_dvds) | NULL | Who borrowed the media |