1. TechEd 2013
1/17/2019 6:32 PM
© 2013 Microsoft Corporation. All rights reserved. Microsoft, Windows, 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. EF in Core Business Apps & Domain-Driven Design Approaches
1/17/2019 6:32 PM
DEV-B336
EF in Core Business Apps & Domain-Driven Design Approaches
Julie Lerman
© 2013 Microsoft Corporation. All rights reserved. Microsoft, Windows, 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.

3. Julie Lerman consultant/mentor contact blog book web site
Microsoft MVP, INETA Speaker, ASPInsider, MCP, VTdotNET Leader
contact
blog
theDataFarm.com/blog twitter
@julielerman
book web site
LearnEntityFramework.com

4. Goals EF in your Architecture DDD Bounded Context Entities &
Aggregates
Repository Pattern(s)
& Unit of Work

5. UI
& some Logic
Business Logic
LINQ
Data Access
Database

6. Separation of Concerns
Extensible
Adaptable
Testable
Maintainable
Sensible!

7. UI Entity Framework Database Service Layer Business/Domain Layer
Repository/Unit of Work
Infrastructure/Data Access
Entity Framework
Tests
Tests
LINQ
Database

8. Considering Context

9. The “We Sell Stuff” Domain
Entity Framework DbContext
Sales
Customers
Orders
Products
Returns
Shipments
Promotions
Payments
Shippers
Employees
SalesPeople
SalaryHistory

10. “bounded context” Delimits the applicability of a particular model.
BOUNDING CONTEXTS gives team members a clear and shared understanding of what has to be consistent
and
what can develop independently.
- Domain Driven Design, Eric Evans 2003

11. - Domain Driven Design, Eric Evans 2003

12. Bounded Contexts within a Domain
Billing
Sales
Customer Service
Shipping
Marketing
Returns
Human Resources

13. Bounded Contexts within a Domain
Billing
Sales
Order
Customer Service
Customer Service
Order
Shipping
Customer
Customers
Customer
Items
Shippers
Payments
SalesPerson
SalesPeople
Customer
Order
Credit
Addresses
ShipAddress
Shipments
ContactHistory
Marketing
Returns
Customer
Promotion
Order
Human Resources
Items
Customers
Employee
Customer
Communications
SalaryHistory
RMA

14. Bounded Contexts within a Domain
Billing
Sales
Invoice
Customer Service
Customer Service
Order
Shipping
Payee
Customers
Customer
ItemsOrdered
Shippers
Payments
SalesPerson
SalesPeople
Purchaser
ItemsToShip
Credit
Addresses
ShipAddress
“Ubiquitous Language”
Shipments
ContactHistory
Marketing
Returns
Recipient
Promotion
ItemReturned
Human Resources
Order
Contacts
Employee
Customer
Communications
SalaryHistory
RMA

15. Entities, Value Objects, Aggregates & Roots

16. Aggregate : Graph of Objects
“Parent” Entity
Aggregate Root
Collection<EntityA>
EntityA
EntityA
EntityA
Entity B

17. Aggregates & Aggregate Roots
The Purchase
Customer
Order
Stuff I Want ID

18. Sometimes . . .
All You Need Is CRUD

19. So . . .
What about
those mappings?
Aggregate Roots
Value
Objects

20. Can EF Handle Your Domain?
Invoice
Payee
Domain Model
Payments
Invoice
Credit
Payee
Domain Model
Payments
Payments
DB Mappings,
DB concerns,
Follow EF rules
Persistence
Model
Customers
Credit
Invoices
Credits
Entity Framework/Queries/Commands
Legacy
Database
New
Database

21. Repository & Unit of Work

22. Repository Essential:
“Encapsulate
Redundant
Data Access
Code”

23. UI Entity Framework Database Service Layer Business/Domain Layer
Repository/Unit of Work
Infrastructure/Data Access
Entity Framework
Tests
Tests
LINQ
Database

24. Basic Repository Get Store Remove Persist GetOrderById GetAllOrders
GetCurrentOrders
GetCachedOrders
GetOrdersForCustomer
GetOrdersForProduct
RemoveOrder
Remove
AddOrder
Persist

25. Many variations… One repo per aggregate? One repo per type?
Read repos?
Write repos?
One repo per context?

26. Order Items Customer Orders
Address Repo
Get
Store
Send to DB
Re move
Order Repo
Get
Store
Send to DB
Remove
DbContext
DbContext
Customer
Repo
Get
Store
Send to DB
Remove
Customer
Orders
Addresses
Aggregate
Root
DbContext

27. Summary Save database concerns for *later*
1/17/2019 6:32 PM
Summary
Save database concerns for *later*
Bounding contexts reduces complexity
Sometimes CRUD is all you need
Use Aggregate Roots to manage graph objects
Repositories are a gateway to your data
Aiming for Testability can Aid in Separating Concerns
© 2013 Microsoft Corporation. All rights reserved. Microsoft, Windows, 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.

28. Summary Pluralsight On-Demand Training: JulieL.me/PS-Videos
1/17/2019 6:32 PM
Summary
Pluralsight On-Demand Training: JulieL.me/PS-Videos
MSDN Developer Center: msdn.com/data/ef
EF Team: blogs.msdn.com/adonet
LearnEntityFramework.com
Programming Entity Framework: DbContext by Julie Lerman and Rowan Miller, O’Reilly Media, Feb
“Domain Driven Design” Eric Evans, Addison-Wesley, 2003
“Implementing Domain Driven Design”, Vaughn Vernon, 2013
“N-Layered Domain-Oriented Architecture Guide with .NET 4.0” by César de la Torre, Unai Zorrilla, Javier Calvarro and Miguel Ángel Ramos (May 20, 2011)
domaindrivendesign.org
“Separation of Concerns”, MSDN Magazine,
© 2013 Microsoft Corporation. All rights reserved. Microsoft, Windows, 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.

29. Julie Lerman consultant/mentor contact blog book web site
Microsoft MVP, INETA Speaker, ASPInsider, MCP, VTdotNET Leader
contact
blog
theDataFarm.com/blog twitter
@julielerman
book web site
LearnEntityFramework.com

30. 1/17/2019 6:32 PM
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© 2013 Microsoft Corporation. All rights reserved. Microsoft, Windows, 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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msdn
Resources for IT Professionals
Resources for Developers
© 2013 Microsoft Corporation. All rights reserved. Microsoft, Windows, 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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© 2013 Microsoft Corporation. All rights reserved. Microsoft, Windows, 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.

33. 1/17/2019 6:32 PM
© 2013 Microsoft Corporation. All rights reserved. Microsoft, Windows 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.
© 2013 Microsoft Corporation. All rights reserved. Microsoft, Windows, 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.