Entity Framework
- 2. Agenda ● ORM ● EF Modelling ● LINQ ● EF Inheritance ● EF Concurrency
- 3. Why Database Layer Object Impedance Mismatch - RDBMS and OOP Object Conversions - RDBMS to OOP and OOP to RDBMS Needs Easy Conversion Process - Rise of ORM
- 4. ORM? Many Frameworks - EF, NH, LINQ to SQL RDBMS to NoSQL Support Single RDBMS Support to Various RDBMS Support DB Layer Uniformity Across the Organization
- 5. Entity Framework - Roadmap
- 6. EF - Key Terms Entity Context - Object Context, Db Context Deferred Execution POCO - Plain Old CLR Object LINQ to Entities, Entity SQL Mapping, Conceptual Model, Storage Model Projections
- 7. EF - Resultant Objects IEnumerable vs IQueryable
- 8. EF - Loading Lazy, Eager Loading and Explicit Loading Loading Navigation Properties 1. LazyLoadingEnabled = true 2. LazyLoadingEnabled = false & Include(“{Navigation Property}”) 3. LazyLoadingEnabled = false & {Navigation Property}.Load()
- 10. Modelling - .edmx - Types Database First Model First
- 11. Modelling - Database First Reverse engineer model in EF Designer Classes auto-generated from model Preferred approach for existing database
- 12. Hands On Database First - Tables, Stored Procedures, Views, Functions Update Model
- 13. Modelling - Model First Create model in EF Designer Generate database from model Classes auto-generated from model Preferred approach for new database.
- 14. Hands On Model First - Create Model, Generate Database Update Model
- 15. Modelling - Code First Define classes and mapping in code Database created from code Migrations apply model changes to database Preferred approach for new database. Generally preferred in Agile/Scrum
- 16. Modelling - Fluent Api, Configuration and Conventions Fluent Api - Chaining Api Configuration with Fluent Api Conventions
- 17. Hands On Code First - Create Classes with Conventions only Database Generation Database Migration
- 18. EF - CRUD
- 19. EF - Read Operation
- 20. EF - Create - Single Record
- 21. EF - Create - Multiple Records
- 22. EF - Update Record
- 23. EF - Delete Record
- 24. Homework AddressBook - Design Db and Do CRUD operations on all entities
- 25. EF - LINQ Filtering, Ordering Joining Grouping
- 26. EF - LINQ - Filtering, Ordering
- 27. EF - LINQ - Joining
- 28. EF - LINQ - Grouping
- 29. Homework Full Outer Join Possible? Use of “let” variable
- 30. EF - Code First Conventions Data Annotations FluentApi
- 31. EF - Code First - Conventions Convention: Table Name Default: Entity + s (e.g Users) Convention: Primary Key Default: Id Convention: Foreign Key Relation Default: Entity + Id (e.g SubscriptionId)
- 32. EF - Code First - Data Annotations Annotation: Table => Table(“{Name”}) Annotation: Key => Key Annotation: ForeignKey => ForeignKey(“{Navigation Property”}) => ForeignKey(“{Property”})
- 33. EF - Code First - Fluent Api
- 34. Homework AddressBook - Design Db and Do CRUD operations on all entities Executing Raw SQL - Plain, Stored Procedures
- 35. EF - Inheritance Strategy - TPH
- 36. EF - Inheritance Strategy - TPH Needs a column, discriminator, that will used to identify exact type. Retrieving Type in TPH Code First Configuration Gives better performance but there are many duplicate data and nullable columns.
- 37. EF - Inheritance Strategy - TPT
- 38. EF - Inheritance Strategy - TPT Each entity maps to table. So CUD operations are faster Code First Configuration Retrieval is slower than TPH as it needs joins with base class/table.
- 39. EF - Inheritance Strategy - TPC
- 40. EF - Inheritance Strategy - TPC Each concrete entity maps to table. Code First Configuration Properties of abstract entity are combined with concrete entity and many data/columns duplications. EDMX designer does not support this mapping. Manual modification is required.
- 41. EF - Relationships One to One One to Many Many to Many
- 42. EF - Relationships - One to One
- 43. EF - Relationships - One to Many
- 44. EF - Relationships - Many to Many
- 45. Hands On One to One One to Many Many to Many
- 47. EF - Concurrency - Optimistic None: Default and there is no concurrency Fixed: Original value of concurrency column is included in where part while generating SQL Rows are not locked. Read operation can be never locked
- 48. EF - Concurrency - Optimistic Sample Code
- 49. EF - Concurrency - Pessimistic Involves database locking operations. So it is slow Use Transaction to achieve it Read operation can be locked
- 50. Questions
- 51. Thank you
- 52. EF - Advance
- 53. Table Splitting After little bit experience, it is worth
- 54. Bounded Contexts After little bit experience, it is worth
- 55. EF - Unit Testing After little bit experience, it is worth
- 56. EF - Patterns After little bit experience, it is worth
Editor's Notes
- #50: http://www.codeproject.com/Articles/114262/ways-of-doing-locking-in-NET-Pessimistic-and-opt