The Application: The Database Module

 @doc """
Create the database table required for the bookstore
"""
def setup do
  run_query(:setup_table_books, [])
end
@doc """
Delete the database table required for the bookstore
"""
def teardown() do
  run_query(:teardown_table_books, [])
end
@doc """
Add a new book to the inventory, with no copies of it
"""
def add_book(isbn, title, author) do
  add_book(isbn, title, author, 0, 0)
end
@doc """
Add a new book to the inventory, with a pre-set number of
owned and available copies
"""
def add_book(isbn, title, author, owned, avail) do
  bin_title = :erlang.iolist_to_binary(title) 
  bin_author = :erlang.iolist_to_binary(author)
  case run_query(:add_book, [isbn, bin_title, bin_author, owned, avail]) do 
    {{:insert, 0, 1}, []} -> :ok
    {:error, reason} -> {:error, reason}
    other -> {:error, other}
  end
end
@doc """
Add a copy of the book to the bookstore's inventory
"""
def add_copy(isbn) do
  handle_single_update(run_query(:add_copy, [isbn]))
end
@doc """
Borrow a copy of a book; reduces the count of available copies by one. Who borrowed the book is not tracked at this moment and is left as an exercise to the reader.
"""
def borrow_copy(isbn) do
  handle_single_update(run_query(:borrow_copy, [isbn])) 
end
@doc """
Return a copy of a book, making it available again
"""
def return_copy(isbn) do
  handle_single_update(run_query(:return_copy, [isbn]))
end
@doc """
Search all books written by a given author. The matching is loose and so
searching for `Hawk' will return copies of books written by `Stephen
Hawking' (if such copies are in the system)
"""
def find_book_by_author(author) do
  handle_select(
    run_query(
      :find_by_author,
      [:erlang.iolist_to_binary(['%', author, '%'])] )
    )
  )
end
@doc """
Find books under a given ISBN
"""
def find_book_by_isbn(isbn) do
  handle_select(run_query(:find_by_isbn, [isbn]))
end
@doc """
Find books with a given title. The matching us loose and searching
for `Test' may return `PropEr Testing'.
"""
def find_book_by_title(title) do
  handle_select(
    run_query(
      :find_by_title,
      [:erlang.iolist_to_binary(['%', title, '%'])]
    )
  )
end