Lazy Loading for EF Core
Inspired by and partially based on the blog post: https://weblogs.asp.net/ricardoperes/implementing-missing-features-in-entity-framework-core-part-6-lazy-loading
Enabling LazyLoading in EF Core is extremely easy with this library. You just need to call UseLazyLoading() (see step 2 below).
However, you will need to slightly modify your entity classes, but just the References, not the Collections (see step 3 below).
Reference the Microsoft.EntityFrameworkCore.LazyLoading NuGet package (https://www.nuget.org/packages/Microsoft.EntityFrameworkCore.LazyLoading/).
Call UseLazyLoading() on the DbContextOptionsBuilder when creating the DbContext.
public class MyDbContextFactory : IDbContextFactory<MyDbContext> { private readonly bool _isLazy; public MyDbContextFactory (bool isLazy) { _isLazy = isLazy; } public MyDbContext Create(DbContextFactoryOptions options) { var dbContextOptionsBuilder = new DbContextOptionsBuilder<MyDbContext>(); dbContextOptionsBuilder.UseSqlServer("<some_connection_string>"); // Here we enable LazyLoading dbContextOptionsBuilder.UseLazyLoading(); return new MyDbContext(dbContextOptionsBuilder.Options); } }
In your model you need to declare References using the type LazyReference<T>. Collections don't require additional configuration in your model, just use the ICollection<> type.
public class Parent { public ICollection<Child> Childs { get; set; } } public class Child { private LazyReference<Parent> _parentLazy = new LazyReference<Parent>(); public Parent Parent { get { return _parentLazy.GetValue(this); } set { _parentLazy.SetValue(value); } } }
That's all, LazyLoading enabled! It was so easy, wasn't it?