1. Entity Framework 4 Deep Dive
Tech Ed North America 2010
5/15/2018 4:47 AM
Required Slide
SESSION CODE: DEV305
Entity Framework 4 Deep Dive
Tim Laverty –
Diego Vega –
Program Managers
Microsoft Corporation
© 2010 Microsoft Corporation. All rights reserved. Microsoft, Windows, Windows Vista and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries.
The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.

2. Goals Answers to common “depth” questions
Focus on real-world scenarios
Shortcomings of EF and workarounds

3. Agenda How do I: Map classes to database structures?
Use patterns such as Repository?
Write unit tests for apps using EF?
Use EF in disconnected scenarios?
Improve EF query perf?

4. How do I map classes to database structures?
EF allows flexibility in mapping relational structures to OO structures
Common mapping questions:
Inheritance
Mapping a single table to multiple entities
Mapping Stored Procedures

5. Tech Ed North America 2010 Tim Laverty Program Manager Microsoft
Mapping
Tim Laverty Program Manager Microsoft
DEMO
© 2010 Microsoft Corporation. All rights reserved. Microsoft, Windows, Windows Vista and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries.
The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.

6. EF Mapping Capabilities
Inheritance
Table per Hierarchy
Table per Type
Table per Concrete Type
Hybrids
Many entities to one table
Stored Procedures
Many tables to one entity
Abstract Entities
Associations within EntitySets
Associations across EntitySets
Store-side discriminators
EDM-side discriminators
QueryViews, Defining Query, CommandText

7. Repository Pattern – Overview
Why:
Cleaner separation of concerns
Greater control
Easier testability
How:
Simple class with simple interface
Pretends to be just a collection
Runs queries & updates on the application’s behalf
Data Access Framework
Database
Business logic, UI, etc.
Repository
Data Access Framework
Database

8. Repository Pattern using Entity Framework
Diego Vega
Program Manager
Microsoft Corporation
Demo

9. Repository Pattern – Recap
Repositories are easy with EF!
Best Practices:
Make the repository’s interface as simple as possible
Create separate repositories for each “aggregate”
Keep other layers “persistence ignorant”
Multiple repositories can share same ObjectContext as “unit of work”
Popular additions:
Query methods return IQueryable<T>
Using “specification pattern”, e.g. repository.Find(c=>c.Id == id)
Repository<T> base class

10. Testability using Entity Framework
Why:
Test business logic, not database
Lightning fast unit tests!
How: swap data access code with in-memory test doubles
Choice #1: replace repository
Choice #2: replace context interface
LINQ only
Repository
ObjectContext
Database
Business logic, UI, etc.
Real Repository
Fake for context interface
In-memory data
Fake Repository
In-memory data

11. Testability using Entity Framework
Diego Vega
Program Manager
Microsoft Corporation
Demo

12. Testability with Entity Framework – Recap
Testability is easy with EF4!
Best practices:
Build simple repository interface
Swap repository with in-memory test double
Alternate route: define simple interface for context
Still run tests against database often
Things to avoid:
Don’t try to mock the data access framework!

13. N-Tier with Entity Framework
Why:
App split by machine boundary
Need to serialize object graphs
Save changes made elsewhere
How: use WCF with
Self-Tracking Entities
WCF Data Services, OData
WCF RIA Services
Your own data transfer objects
Data Access
Database
Presentation
Business logic

14. Self-Tracking Entities
Diego Vega
Program Manager
Entity Framework
Demo

15. N-Tier with Entity Framework – Recap
EF4 N-Tier improvements:
New low level state management API
Self-Tracking Entities
Best practices:
Use standard change tracking when possible
Use Self-Tracking Entities if sharing entity types is acceptable
Create data transfer objects when low coupling is needed
Other technologies to learn about:
WCF Data Services - bit.ly/learndataservices
WCF RIA Services - bit.ly/learnriaservices

16. How do I improve EF perf? – Factors
Query complexity and use
Model size and complexity
Inheritance hierarchies
Database Schema Design

17. Strategies for making EF queries run faster
Tech Ed North America 2010
5/15/2018 4:47 AM
Strategies for making EF queries run faster
Tim Laverty Program Manager Microsoft
DEMO
© 2010 Microsoft Corporation. All rights reserved. Microsoft, Windows, Windows Vista and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries.
The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.

18. EF load steps for startup and on first query?
EF Startup
Loads Model Metadata
Generates EF Query Views
(or upon first query)
First Time Query Execution
EF Query Translation
EF Query Caching
Manual with LINQ
queries.
Result Shaper Caching

19. How do I improve EF query perf – Recap
Round trips
Lazy Loading
Multiple Queries
Connection
Overuse Danger!
Use Include
No Updates!
Use NoTracking
Expensive 1st time
Cached
Compile Query
Large data
No Updates!
Projection
Separate Queries
EF offers
fixup
Stored Procs/Views
Not Composable

20. Related Content Required Slide
Speakers, please list the Breakout Sessions, Interactive Sessions, Labs and Demo Stations that are related to your session.
Tech Ed North America 2010
5/15/2018 4:47 AM
Related Content
DEV324: Data Development GPS: Guidance for Choosing the Right Data Access Technology – Monday | 1:00 – 2:15 PM | Rm 383
DEV208: Open Data for the Open Web – Tuesday | 5:00 – 6:15 PM | Rm 279
DEV205: Overview of the Microsoft ADO.NET Entity Framework – Wednesday | 1:30 – 2:45 PM | Auditorium B
DEV303: Building RESTful Applications with the Open Data Protocol – Wednesday | 3:15 – 4:30 PM | Rm 283
DEV323: Best Practices: Creating OData Services Using WCF Data Services – Wednesday | 5:00 – 6:15 PM | Rm 295
ARC306: Open Data for the Enterprise – Thursday | 8:00 – 9:15 AM | Rm 288
BOF05-DV: Microsoft ADO.NET Entity Framework 4.0: What’s Your Take? – Thursday | 9:45-11:00 AM
DEV13-HOL: Building Applications and Services Using Open Data Protocol
DEV11-HOL: Using the Entity Framework in Microsoft .NET Framework 4.0 and Microsoft Visual Studio 2010
TLC-77: Microsoft SQL Server R2 Data Development (ADO.NET, OData, XML) – TLC Yellow
© 2010 Microsoft Corporation. All rights reserved. Microsoft, Windows, Windows Vista and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries.
The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.

21. Additional Resources and Announcements
MSDN Data Developer Center:
ADO.NET Team Blog:
OData Blog:
WCF Data Services Team Blog:
EF Design Blog:
Data Platform Development Forums: and click on the “Forums” tab
Patterns and Testability:
Come to the Data Development station in the DAT Track Area (yellow section of the TLC) to register for a Zune HD give-away!

22. Required Slide
Track PMs will supply the content for this slide, which will be inserted during the final scrub.
Tech Ed North America 2010
5/15/2018 4:47 AM
Track Resources
Visual Studio –
Soma’s Blog –
MSDN Data Developer Center –
ADO.NET Team Blog –
WCF Data Services Team Blog –
EF Design Blog –
© 2010 Microsoft Corporation. All rights reserved. Microsoft, Windows, Windows Vista and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries.
The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.

23. Resources Learning Required Slide www.microsoft.com/teched
Tech Ed North America 2010
5/15/2018 4:47 AM
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© 2010 Microsoft Corporation. All rights reserved. Microsoft, Windows, Windows Vista and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries.
The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.

24. Complete an evaluation on CommNet and enter to win!
Tech Ed North America 2010
5/15/2018 4:47 AM
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Complete an evaluation on CommNet and enter to win!
© 2010 Microsoft Corporation. All rights reserved. Microsoft, Windows, Windows Vista and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries.
The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.

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26. Tech Ed North America 2010 5/15/2018 4:47 AM
© 2010 Microsoft Corporation. All rights reserved. Microsoft, Windows, Windows Vista and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries.
The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.
© 2010 Microsoft Corporation. All rights reserved. Microsoft, Windows, Windows Vista and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries.
The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.

27. Appendix

28. Required Slide Tech Ed North America 2010 5/15/2018 4:47 AM
© 2010 Microsoft Corporation. All rights reserved. Microsoft, Windows, Windows Vista and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries.
The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.