Multiple authors for a Book

Question

In the below example, the book titled 'Collapse of the Dollar' has multiple authors.
create table books
(surrId number(5),
book_id number(7),
isbn number (10),
title varchar2(100) ,
Author varchar2(100)
insert into books values (1, 457, 8478, 'Perilous Power' , 'Noam Chomsky');
insert into books values (2, 458, 2345, 'Macbeth' , 'Shakespeare');
insert into books values (3, 459, 6789, 'Collapse of the Dollar' , 'James Turk');
insert into books values (4, 459, 6789, 'Collapse of the Dollar' , 'John Rubino');
col title format a35
col author format a15
col title format a15
set lines 200
SQL> select * from books;
    SURRID    BOOK_ID       ISBN TITLE                               AUTHOR
         1        457       8478 Perilous Power                      Noam Chomsky
         2        458       2345 Macbeth                             Shakespeare
         3        459       6789 Collapse of the Dollar              James Turk
         4        459       6789 Collapse of the Dollar              John RubinoI need to write a query whiich returns book details but it should identify records (ie. Titles) with multiple authors and return the record with Authors separated with pipe ('|') like (no need of SURRID column )
expected output
      -- no need to retrieve surrogate ID
  BOOK_ID       ISBN TITLE                               AUTHOR
      457       8478 Perilous Power                      Noam Chomsky
      458       2345 Macbeth                             Shakespeare
      459       6789 Collapse of the Dollar              James Turk|John Rubino
      Related question on the above Table design (Create table DDL shown above):
A table storing book details can only be designed like above. Right ? I mean, the duplication of records for one book because of multiple authors cannot be avoided. Right ?
One wonders how Amazon has desined its books table :)

Answer 1

Hi,
Pete_Sg1 wrote:
I need to write a query whiich returns book details but it should identify records (ie. Titles) with multiple authors and return the record with Authors separated with pipe ('|') like (no need of SURRID column )Get there : {message:id=9360005}
and scroll down to "string aggregation"
Pete_Sg1 wrote:
A table storing book details can only be designed like above. Right ? I mean, the duplication of records for one book because of multiple authors cannot be avoided. Right ? I would have had a table for books, and a separate one for authors, and a 3rd one for their relations :
create table books
book_id integer,
title varchar2(100),
etc...
create table authors
author_id integer,
name varchar2(100),
etc...
create table book_authors
book_id integer,
author_id integer
);You could also have only 2 tables book and authors (with authors table having a fk column to book_id).
It would depends if the author is supposed to remain unique throught different books.
- The 3 tables model would allow a single update on author information to be automatically "propagated" to all book he participed in.
- The 2 tables model would allow to have different information for each participation of the author to different books (but would certainly "duplicate" part of the data about the author)
One can also have even more tables to totally avoid data "duplication".