Why does PersistentObjectSpace sometimes return a proxy and sometimes return an object? - entity-framework

Question

The debugger shows me that in the following code
_taxRate =
PersistentObjectSpace.FindObject<TaxRate>(CriteriaOperator.Parse("[TaxCodeId] = ?", TaxCodeId));
var _product2 =
PersistentObjectSpace.FindObject<Product>(CriteriaOperator.Parse("[ItemId] = ?", ItemId));
_taxRate is a poco but _product2 is a proxy
The objects are
[Table("TaxCode")]
[DefaultProperty("TaxCode")]
[ImageName("BO_List")]
public class TaxRate : BasicBo
{
[Key] public short TaxCodeId { get; set; }
[Required]
[RuleRequiredField(DefaultContexts.Save)]
[StringLength(20, ErrorMessage = "The field cannot exceed 20 characters. ")]
public string TaxCode { get; set; }
[Required]
[RuleRequiredField(DefaultContexts.Save)]
public decimal Percentage { get; set; }
public override string ToString()
{
return TaxCode;
}
}
and
[Table("MyExtItem")]
[DefaultProperty("ProductCode")]
[NavigationItem("Config")]
public class Product : BasicBo
{
[Key]
public int ItemId { get; set; }
public string ItemName { get; set; }
[Column("Item Number")] public string ProductCode { get; set; }
[MaxLength(10)] public string UnitName { get; set; }
public int? ProductImageId { get; set; }
[ForeignKey("ProductImageId")] public virtual ProductImage ProductImage { get; set; }
[ForeignKey("ItemId")] public virtual ExtMaterialProperty ExtMaterial { get; set; }
}

Answer 1

This is expected behaviour when EF is configured to support lazy loading.
TaxRate holds no references to other entities so EF can return a concrete instance.
Product contains two references to other entities, ProductImage and ExtMaterial.
If I run the code:
var product = context.Products.Single(x => x.ItemId == itemId);
to get a product, EF uses a proxy in order to be prepared for when I try to access something like ProductImage.
var imageName = product.ProductImage.Name;
You can disable the proxies using Configuration.ProxyCreationEnabled on the DbContext. (EF6) This does mean that any references will need to be eager loaded or explicitly loaded, as Lazy Loading will not function without the proxies.