Entity framework 4.3 with required association

Question

I'm a very strange behavior with EF code first approach and associations. I have two entities: ``` public class GlobalKpiSectionn { public GlobalKpiSection() { this.Regions = new HashSet(); } public virtual ICollection Regions { get; protected set; } } public class Region { public int RegionId { get; set; } public bool IsMain { get; set; } [Required] public virtual GlobalKpiSection KpiSection { get; set; } } ``` I need required attribute on KiSection property in order to get cascade deletes. The problem is the following - in this code: ``` var mainRegion = context.Regions.Single(x => x.RegionId == id); mainRegion.IsMain = true; context.SaveChanges(); ``` I'm getting exception that Required field is not initialized. But it is present just not loaded. I don't what to write everywhere explicit includes for properties when I use this entity. What can I do to overcome this? UPDATE The reason why I'm sure its lazy loading issue is that: ``` var primaryRegion = context.Region…

Accepted Answer

That is why you should not use data annotations. Data annotations are wrong feature because they do both mapping and validation (violation of single responsibility) - as you see it is not always what you want. So your current options are:

- Turn off validation in `context.Configuration.ValidateOnSaveEnabled = false`

- Expose non nullable `KpiSectionId` foreign key property in your `Region` entity (you will not need `Required` attribute on your navigation property).

- Use fluent API instead of data annotations :

Example:

```
modelBuilder.Entity<GlobalKpiSection>()
            .WithMany(s => s.Regions)
            .HasRequired(r => r.KpiSection);
```

Entity framework 4.3 with required association

Solution

Problem