DBIx-DataModel is an object-relational mapping framework for Perl5. Schema declarations are inspired from UML modelling. The API provides efficient interaction with the DBI layer, detailed control on statement execution steps, flexible and powerful treatment of database joins. More on http://search.cpan.org/dist/DBIx-DataModel. Talk presented at YAPC::EU::2011 Riga (updated from a previous version presented at FPW2010).

1. DBIx::DataModel 2.0 in detail YAPC::EU::2011, Riga [email_address] Département Office

3. Object-Relational Mappers

4. Perl and databases Database DBD driver DBI Object-Relational Mapper Perl program

5. ORM principle r1 r2 ... c1 c2 c3 ... c3 c4 +c1: String +c2: String +c3: class2 r1 : class1 RDBMS r2 : class1 RAM table1 table2

7. The Unified Modeling Language (UML)

8. Example : CPAN model Author Distribution Module 1 * 1 * * multiplicity role class association dependent _distribs * prereq _modules contains ► assoc. name composition depends_on ►

9. Modelling a schema

10. Architecture Schema Source Table Join Statement My::DB My::DB::Table_n My::DB::AutoJoin:: row statement row DBIx::DataModel classes application classes objects schema  quite similar to DBI architecture (dbh, sth)

13. Meta-Architecture Schema Table Join My::DB My::DB::Table_n My::DB::Auto_join Meta::Source Meta::Table Meta::Join meta::table meta::join meta::schema Meta::Schema Meta::Path Meta::Association Meta::Type meta::assoc meta::path meta::type

14. Data retrieval

19. Arguments to select()

26. Row objects

30. Statement objects

31. Statement: an encapsulated query statement meta::source My::Source 1 1 * * schema dbh 0..1 * row next() / all() My::Schema meta::schema in single-schema mode in multi-schema mode singleton()

32. Statement lifecycle new sqlized prepared executed schema + source data row(s) new() sqlize() prepare() execute() bind() refine() bind() bind() bind() execute() next() / all() blessed column types applied -post_bless -pre_exec -post_exec -post_SQL

35. Database joins

39. Insert / Update

45. Other features

53. Conclusion

57. THANK YOU FOR YOUR ATTENTION

58. Bonus slides

61. Many-to-many implementation author_id author_name e_mail 1 * 1 * * * Author distrib_id module_id Dependency distrib_id distrib_name d_release author_id Distribution module_id module_name distrib_id Module 1 1 link table for n-to-n association

62. Writing SQL SQL is too low-level, I don't ever want to see it SQL is the most important part of my application, I won't let anybody write it for me