Arun Stephens

Entity Framework 4 many-to-many

I had another problem with EF4 today. Code that worked fine in .NET 3.5 didn’t work after I regenerated the entity model using Visual Studio 2010. I found an answer, again on Stack Overflow: It turns out that the generator decided that one of my foreign keys in an associative table should have a StoredGeneratorPattern of Identity, meaning it thought it was an identity column. When it isn’t. But updating the XML as suggested in the answer above fixed it. Read more →

1..0 or 1 relationships in Entity Framework

I came across this problem today when migrating a project from VS 2008/.NET 3.5 to VS 2010 RC1/.NET 4.0. I don’t actually think it’s a VS 2010 thing, though. I have two entities A and B. There is a navigation property on A, and it can have either one or no instances of B. B’s foreign key is to A’s primary key (obviously) but B also has its own primary key. Read more →

Entity Framework: Part 2

I have been reading a bit of the documentation about the ADO.NET Entity Framework. There are a few passages that relate to my previous post: Because referenced objects are not automatically loaded, you must call the Load method on the entity reference to load the related object data into the object context. You can also specify a query path that defines which related objects to load with returned objects. For more information, see Querying Data as Objects (Entity Framework). Read more →