Question

From the code sample of this question, I added a string property to my wrapper, and then I only want it for GUI and tests purposes, I don’t want this string property to be persisted into the database. The wrapper looks the same as sampled in the linked question with this add-on:

public string StringValue {
    get {
        return stringValues[Value];
    }
    set {
        if (stringValues.Contains(value))
            t = (StreetType)stringValues.Single(s => s == value).IndexOf(value);
    }
}

public static implicit operator string(StreetTypeWrapper w) {
    return w == null ? stringValues[0] : w.StringValue;
}

public static implicit operator StreetTypeWrapper(string s) {
    return new StreetTypeWrapper() { StringValue = s };
}

Not to mention that I never changed the StreetTypeMapping complex type mapping class to include this new property, I don’t want it in the database, but EF keeps persisting it anyway, though I only mapped the Value property of this complex type.

Is there something I do wrong for this to happen?

How can I avoid this annoying behaviour?
(EF decides for me what to map though I specified what to map)

Answer 1

you can add the [NotMapped] attribute to the property

[NotMapped]
public string StringValue { .... }

if there is some way to make the property read-only, then EF will ignnore it also.