// Book-library schema
// Generation unit: table  →  generated/library.py

Table authors {
  id         integer [pk, increment, not null]
  name       varchar [not null]
  birth_year integer
}

Table books {
  id        integer [pk, increment, not null]
  title     varchar [not null]
  isbn      varchar
  author_id integer [not null, ref: > authors.id]
}

Table borrowers {
  id    integer [pk, increment, not null]
  name  varchar [not null]
  email varchar [not null]
}

Table loans {
  id          integer [pk, increment, not null]
  book_id     integer [not null, ref: > books.id]
  borrower_id integer [not null, ref: > borrowers.id]
  loan_date   varchar [not null]
  return_date varchar
}