The example library

Most examples in this documentation use the same small database: a library with authors, books, members, and loans. Keeping one familiar set of tables makes it easier to focus on the concept each page is teaching.

The tables

Table	Columns
authors	author_id (serial, primary key), name (text), birth_year (int)
books	book_id (serial, primary key), title (text), author_id (int → authors), published (int), isbn (text, unique)
members	member_id (serial, primary key), name (text), joined (date)
loans	loan_id (serial, primary key), book_id (int → books), member_id (int → members), loaned_on (date), returned_on (date)

The relationships

• An author has many books. books.author_id points at authors.author_id — a one-to-many relationship.
• Members borrow books. Each row in loans ties one book to one member, so loans connects books and members — a many-to-many relationship expressed through a bridging table.

You will build these tables and relationships step by step in Build the library. Individual reference pages use whichever part of this schema illustrates the command at hand.