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.

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.

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

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

UI & some Logic Business Logic LINQ Data Access Database

Separation of Concerns Extensible Adaptable Testable Maintainable Sensible!

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

Considering Context

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

“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

- Domain Driven Design, Eric Evans 2003

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

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

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

Entities, Value Objects, Aggregates & Roots

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

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

Sometimes . . . All You Need Is CRUD

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

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

Repository & Unit of Work

Repository Essential: “Encapsulate Redundant Data Access Code”

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

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

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

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

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.

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 22 2012 “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, http://juliel.me/Jhp6Pp © 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.

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

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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.