Querying complex script with lots of join statement

[vkuchyn]

Hi The question is it possible to use this project for querying complex scripts where lots of joins. For example, I need to query books with authors (classic example) and map them to next structure

interface Book{
   List<Author> authors();
   String title();
}

interface Author {
  String name();
  String secondName();
}

interface Library {
   List<Book> books();
}

Here is my database. Suggest an author can write only one book for simplicity books

id	title
1	Elegant Objects
2	Thinking in Java
3	Java Concurrency in Practice

authors

id	name	second_name	book_fk
1	Egor	Bugayenko	1
2	Bruce	Eckel	2
3	Brian	Goetz	3
4	Tim	Peierls	3
5	Joshua	Bloch	3
6	Joseph	Bowbeer	3
7	David	Holmes	3
8	Doug	Lea	3

And next query

select * from books b join authors a on b.id = a.book_fk;

I would like to map next query to some implementation of interface Library

[dmarkov]

@yegor256 take a look at this issue please and dispatch it somehow, see par.21

[yegor256]

@vkuchyn well, what the problem is exactly with? you just implement that selection in Library.books(). and then in each book you make new queries to retrieve authors. or I missed the point?

[vkuchyn]

@yegor256 I'd like to use join, because with subselect approach we breaks performance conditions

[yegor256]

@vkuchyn I guess it's more a question about object-oriented programming and design than about this library specifically, right? Please post it to my blog, we'll discuss there. Here the ticket may be closed, I think.

[vkuchyn]

@yegor256 yes, you can close the ticket. Shall I post OOP/OOD question to proper topic as comment or there is an option to ask question, create topic, whatever at your blog? Thanks

[yegor256]

@vkuchyn I would suggest to post it here: http://www.yegor256.com/2014/12/01/orm-offensive-anti-pattern.html Otherwise, you can join our Gitter chat and discuss it live with other OOP adepts: https://gitter.im/yegor256/elegantobjects Please, close the ticket (since you're the author of it), thanks