How can I store an Array of Ints in my database, in a single field, using Code First Entity Framework?

Question

What I want to do is store an Array of Ints in my database. I am Using Code First Entity Framework to create my database I can't seem to create a List or Array element in the database. The List item doesn't create a field. I gather that this is because it would need a separate table.

What is the best way to store my array in a single field here. Should I convert the array to a String, or is there an easier way?

My model contains:

public string Title { get; set; }
public List<int> IdArray { get; set; }

Answer 1

NHibernate supports this, but EF doesn't.

If you need to do it the only option is to store it serialized. For example you can do:

• a XML column, and store it serialzed as XML
• a char column, and store it serialized as JSON

EF will not automatically serialize / deserialize it. You should add a property that does the serialization/deserialization for you

public string IdsColumn { get; set; } // Mapped to DB

[NotMapped]
public List<int> Ids
{
    get { return Deserialize(IdsColumn); }
    set { IdsColumn = Serialize(value); }
}

Of course you have to provide the serialization functions implementation, using XMLSerializer or JSON.NET, for example.

If you want this functionality implemented, look here: EF data user voice

For example Richer collection support, including ordered collections and dictionaries of value types

You can vote for it.

Answer 2

Im not too sure of your situation but Most of the time this is never necessary...

Basically if you arrive at such a situation you should look at normalizing your table further. data in tables need to be "atomic". once retrieved as objects it can be in a list.