Question

I have a poco class like this

public Profile
{
    public virtual int ID
    {
        get;
        set;
    }

    public virtual string Description
    {
        get;
        set;
    }

    public virtual bool Enabled
    {
        get;
        set;
    }
}

When i try to update like this

var prof = new Profile(){ ID = 1, Enabled = false };
context.Profiles.Single (s => s.ID == 1);
context.Profiles.ApplyCurrentValues(prof);
context.SaveChanges();

Sql says to me that Description does not allow NULL, but i’m not updating the “Description” column, I want to update just the “Enabled” field.

What’s wrong?

Tks

Answer 1

Try this instead:

var prof = new Profile { ID = 1, Enabled = false };
// Attach prof as unchanged entity
context.Profiles.Attach(prof);
// Get state entry for prof
ObjectStateEntry entry = context.ObjectStateManager.GetObjectStateEntry(prof);
// Set only Enabled property to changed
entry.SetModifiedProperty("Enabled");
context.SaveChanges();

As you can see I didn’t need to load the entity first from database. I was able to set which property was modified on detached entity.