.NET Tips and Tricks

Blog archive

Writing Flexible Entity Framework Methods with Set

Every once in a while I find myself writing one set of code to do something to the Customers collection and then writing almost identical code work with the Orders collection. When I spot that duplicate code, I use the Set method on the DbContext object to find the collection of entities I want and write the code once. I just pass the Type of the object I want to the Set method.

For instance, I could write code like this to work with the Orders collection:

res = ctx.Orders

If I use the Set method, I just have to pass the type of the entity in the collection. For the Orders collection, that's the Order class:

res = ctx.Set(GetType(Order))

You can use the Set method to create general purpose methods in at least two ways. First, you can pass the type of the object to a method that accesses the DbContext object:

Public Sub MyMethod(EntityType As Type)
  res = ctx.Set(EntityType)
  '…code to work with the collection    
End Sub

Alternatively, you can write a generic method and pass the type when you call the method:

Public Sub MyMethod(of T As Class)()
    res = ctx.Set(GetType(T))
End Sub

Posted by Peter Vogel on 05/30/2014 at 9:58 AM


comments powered by Disqus

Featured

  • Microsoft's Lander on Blazor Desktop: 'I Don't See a Grand Unified App Model in the Future'

    For all of the talk of unifying the disparate ecosystem of Microsoft-centric developer tooling -- using one framework for apps of all types on all platforms -- Blazor Desktop is not the answer. There isn't one.

  • Firm Automates Legacy Web Forms-to-ASP.NET Core Conversions

    Migration technology uses the Angular web framework and Progress Kendo UI user interface elements to convert ASP.NET Web Forms client code to HTML and CSS, with application business logic converted automatically to ASP.NET Core.

  • New TypeScript 4.2 Tweaks Include Project Explainer

    Microsoft shipped TypeScript 4.2 -- the regular quarterly update to the open source programming language that improves JavaScript with static types -- with a host of tweaks including a way to explain why files are included in a project.

  • What's Top-Paying .NET Skill, In-Demand Language?

    New tech reports reveal the top-paying .NET skills and most in-demand programming languages in the Microsoft-centric developer landscape.

Upcoming Events