Shared Image table with entity framework - entity-framework

Question

I would like to create a table for images within my database that can be used by several different models. I'm using entity framework and have defined my images class as follows:
public class Images
{
public int ID { get; set; }
public String Name {get; set;}
public byte[] ImageData { get; set; }
public string Type { get; set; }
}
I would then like to link to this from any of my other models that need to hold an image. E.g
public class Project
{
public int ID { get; set; }
public String Name { get; set; }
public DateTime StartDate { get; set; }
public DateTime EndDate { get; set; }
public virtual ICollection<tImages> Images { get; set; }
}
and also
public class User
{
public int ID { get; set; }
public String UserName { get; set; }
public virtual ICollection<tImages> Images { get; set; }
}
The trouble is that entity framework is adding a foreign key for both project and user to the image table. I kind of expected this I guess.
What I want is to define an image key that can be used to index into my image table. I'm just not sure how to define the classes to get this affect. E.g how do I define my entity classes to acheive the result below:
Project Table
//ID Name StartDate EndDate Image
//1 Project1 05/02/2013 06/04/2013 PROJ01IMG
User Table
//ID UserName Image
//1 Bob USER01IMG
Image Table
//ID Name Imagekey ImageData Type
//1 img1 PROJ01IMG 0xFFF00F1 .. etc JPEG
//2 teamphoto PROJ01IMG 0xFEB0011 ..etc JPEG
//3 outline PROJ01IMG 0xFFF0AA3 ..etc PNG
//4 bob USER01IMG 0xFFF01233 ..etc JPEG
Of course it may be that having the foreign keys is the correct approach and I shouldn't worry about it? Its just that I have a lot of models and they all need to store images so I'd rather just have them in one table rather than multiple image table as it will make searching/ galleries etc of all images easier down the line I think.
I get the feeling that this a complete noob question and I'm missing something obvious so apologies if it is.

Answer 1

If you don't want EF to map a FK, and instead you will manually populate a list based on the image key, define your entities like this. But I think you are better off with what you had, using FK's.
public class Project
{
public int ID { get; set; }
public String Name { get; set; }
public DateTime StartDate { get; set; }
public DateTime EndDate { get; set; }
public string ImageKey { get; set; }
[NotMapped]
public List<Image> Images {get; set;}
}
public class User
{
public int ID { get; set; }
public String UserName { get; set; }
public string ImageKey { get; set; }
[NotMapped]
public List<Image> Images {get; set;}
}
I suppose you might try defining your classes like this to see if it's what you want:
public class Images
{
public int ID { get; set; }
public String Name {get; set;}
public byte[] ImageData { get; set; }
public string Type { get; set; }
public virtual User User { get; set; }
public virtual Project Project { get; set; }
}
public class Project
{
public int ID { get; set; }
public String Name { get; set; }
public DateTime StartDate { get; set; }
public DateTime EndDate { get; set; }
}
public class User
{
public int ID { get; set; }
public String UserName { get; set; }
}
That should map a FK to Images in Project as well as in User, which is what I think you're really looking for.