Welcome to OStack Knowledge Sharing Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
794 views
in Technique[技术] by (71.8m points)

entity framework 4.1 - Enums with EF code-first - standard method to seeding DB and then using?

Is there a standard way to using Enums in EF code-first? There seems to be some examples making use of a wrapper class for the enum.

However, I would like to be able to define the enum and have the enum values also seeded into the database using the database initializer. There doesn't seem to be much point in defining the enum and creating a wrapper, if I then have to seed the database table manually from the enum.

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Answer

0 votes
by (71.8m points)

Unfortunately, enums are not natively supported on EF 4.1. Here's one rather known article on how to deal with them: Faking enums on EF 4. It does, however, require a wrapper.

There's a simpler way to map enums in EF 4 however: just create an int property on your class to represent the int value of the enum. That's the property that EF should map, then have a "mini wrapper" property to allow you to use the enum.

public class Appointment 
{   
    public int ID { get; set; }
    public string Description { get; set; }

    // This property will be mapped
    public int DayOfWeekValue { get; set; }

    public DayOfWeek Day
    {
        get { return (DayOfWeek) DayOfWeekValue; }
        set { DayOfWeekValue = (int) value; }
    }
}

public enum DayOfWeek
{
    Monday,
    Tuesday,
    Wednesday,
    Thursday,
    Friday,
    Saturday,
    Sunday
}

On generating the database, EF will happily ignore any type it doesn't know how to map, but the int property will be mapped.

Note: This is taken directly from my answer to another enum and EF question: EF 4.1 Code First - map enum wrapper as complex type


与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome to OStack Knowledge Sharing Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...