mongo.pdf

Transcript

1. Exploring design patterns with MongoDB TAMING THE HORSEPOWERS Morten Holk

   Maate Sr. Developer, Product Manager mhm@configit.com

2. db.GetCollection(''Employee'').Save(employee);

3. One reason that MongoDB is great is that our data

   store uses objects – as well as our OO programming language uses objects JSON in Mongo Shell: C# in Visual Studio:

4. … and objects do seem like a great abstraction for

   … objects

5. MongoDB Solves The Object-Relational Impedence Mismatch • Data Mapping •

   Normalization • Object Identity • Serialization Storing Objects as Objects Utilizing Object Hierarkies With ObjectId() As BSON

6. Your Object is not your Object! Is NOT equal to

   this: And this:

7. Literally 

8. EXPECTATIONS • Data Mapping • Normalization • Object Identity •

   Serialization REALITY • C#/Java objects still needs some mapping to become Mongo Objects • C#/Java objects still needs some normalization • We have not solved the identity problem • Serialization still is not easy

9. Hands on case: Storing employees in a database Take 1

   Illustrating the Challenges

10. Main Procedure • Create object instance • Store object •

    Load object SalesEmployee + Id : ObjectId + Name : String + Value : Int32 Mongo DB
11. None

12. db.GetCollection(''Employee'').Save(employee); Won’t build without MongoDB Reference

13. Won’t build without MongoDB Reference

14. Hands on case: Storing employees in a database Take 2

    ”ActiveRecord Pattern”

15. Main Procedure • Create object instance • Store object •

    Load object SalesEmployee + Id : ObjectId + Name : String + Value : Int32 + Save() + Load() Mongo DB Active Record I

16. Main Procedure • Create object instance • Store object •

    Load object PersistentObject<T> + ObjectId + void Save(T obj) + T Load(ObjectId id) SalesEmployee + Name : String + Value : Int32 Mongo DB DataAccess Domain Active Record II
17. None

18. Hands on case: Storing employees in a database Take 3

    ”Repository Pattern”

19. Main Procedure • Create object instance • Store object •

    Load object Employee + Name : String + Value : Int32 Repository<T> + void Save(T obj) + T Load(ObjectId id) IRepository<T> + Load() + Save() Sales Employee Developer Mongo DB DataAccess Domain Repository Pattern PersistentObject<T> + ObjectId
20. None

21. Hands on case: Storing employees in a database Take 4

    ”DataMapper pattern”

22. Main Procedure • Map Data • Create object instance •

    Store object • Load object Employee + Id : String + Name : String + Value : Int32 Repository<T> + void Save(T obj) + T Load(String id) IRepository<T> + Load() + Save() Sales Employee Developer Mongo DB DataAccess Domain Settings + SetupDatabase() DataMapping DataMapper
23. None

24. Hands on case: Storing employees in a database Take 5

    ”DataMapper pattern II”

25. Main Procedure • Create object instance • Store object •

    Load object Employee + Id : String + Name : String + Value : Int32 Repository<T> + void Save(T obj) + T Load(String id) Employee Repository IRepository<T> + Load() + Save() Sales Employee Developer +BestFriend : Developer Developer Repository Developer Repository Mongo DB DataAccess Domain DataMapper Pattern
26. None