Entity Framework: How to map a complex object to a single varchar column (i.e. save it in serialized form)?

Question

I have an Entity where one of its properties is a complex object. I would like to represent this object in my DB as a serialized string (JSON to be specific).

How can I configure Entity Framework (I'm using v6.0) to map the above to a varchar, rather than the default EF behavior of auto-mapping it to tables and columns?

Answer 1

Unfortunately this kind of property mapping is still not supported by Entity Framework. You probably have to fall back to tricks like this:

public class MyEntity
{
    //...
    [NotMapped]
    public MyComplexType MyComplexType { get; set; }

    public string MySerializedComplexType
    {
        get { return Serialize(MyComplexType); }
        set { MyComplexType = Deserialize(value); }
    }
    //...
}

(Instead of the [NotMapped] attribute you can use modelBuilder.Entity<MyEntity>().Ignore(e => e.MyComplexType) if you prefer Fluent API.)