What type of relationship will there be between the books and authors tables?

The relationship between books and authors tables is usually implemented as a many-to-many relationship.

This is because one book can have multiple authors, and one author can write multiple books.

To implement such a relationship, an intermediate table is created, for example, book_authors, which contains pairs of book_id and author_id.

Example table structures:

CREATE TABLE authors (
  id SERIAL PRIMARY KEY,
  name VARCHAR(255) NOT NULL
);

CREATE TABLE books (
  id SERIAL PRIMARY KEY,
  title VARCHAR(255) NOT NULL
);

CREATE TABLE book_authors (
  book_id INT REFERENCES books(id),
  author_id INT REFERENCES authors(id),
  PRIMARY KEY (book_id, author_id)
);

This approach allows flexible storage and querying of data about authors and books.