Entity Framework

Using CockroachDb with Entity Framework is easy, here is a simple post showing how.

After you save an entity, you may want to send out a notification so other parts of your application can react to the change. This post shows how to do that with MediatR and Entity Framework Core.

Find/FindAsync is a popular way to retrieve a single entity using its primary key with Entity Framework, but by default Entity Framework tracks that entity for changes. This post shows how to turn off tracking for Find/FindAsync.

Here is a way to access objects just after they are saved by Entity Framework and have had a primary key assigned to them.

I left out version number in a package reference and got the exception - Exception has occurred: CLR/System.MissingMethodException An exception of type ‘System.MissingMethodException’ occurred in System.Collections.Concurrent.dll but was not handled in user code: ‘Method not found: ‘System.IServiceProvider.

I have been a fan of Entity Framework for many years, and have relied on using the context within the Configure(..) method in Startup.cs, but that is not available when using top-level statements. This post shows how to use the context within Program.cs.

There are times when firing off the same query in parallel to two or more data stores is a good choice, but normally hitting one, waiting for the response, and only hitting the second if necessary is a better approach. Here I’ll show how to query Redis, and if the key is missing, query MS SQL.

There are times when firing off the same query in parallel to two or more data stores is a good choice, keeping the first response, and canceling the other requests. Here I show how a achieve that even if the Task<> types are different.

Want to see how easy it is to use a SQL Server Docker container with Entity Framework for .NET 6?

Using Entity Framework I occasionally get the following error when reading from the database - `exceptionMessage=Value cannot be null. Parameter name: constructor` My Person class looked like this - 1 public class Person 2 { 3 public Person(string firstname, string lastname) 4 { 5 Firstname = firstname; 6 Lastname = lastname; 7 } 8 9 public Guid PersonId { get; set; } 10 public string Firstname { get; set; } 11 public string Lastname { get; set; } 12 public DateTime SomeDate { get; set; } 13 } There is no way for Entity Framework to know how to instantiate this object because there is no empty constructor.