Overriding code-generated DbContext constructor

Question

I'm sure I've done this before at some stage, but I can't figure out how to now! My scenario:

// This is generated from EDMX
public partial class HOLDbEntities : DbContext
{
    public HOLDbEntities()
            : base("name=HOLDbEntities")
        {
        }
}

Now, I want this connection string to be easily changeable (I want to Implement from the HOLDbEntities), so I need to override this constructor.

I've tried:

public partial class HOLDbEntities
{
    private const string _contextName = "HOLDbEntities";
    public static string ContextName { get { return _contextName; } }

    public HOLDbEntities()
        : base(ContextName)
    {
    }
}

But this throw an error:

HOLDbEntities already defines a member called "HOLDbEntities" with the same parameter types.

I can understand why this errors, but how would I stop the constructor being auto-generated in the first place in order to do what I'm trying to achieve?

Answer 1

The best I can suggest is a factory method:

private HOLDbEntities(string contextName) : base(contextName) { }

public static HOLDbEntities Create() {
    return new HOLDbEntities(ContextName);
}

and use HOLDbEntities.Create() rather than new HOLDbEntities().