在Entity Framework Database First中更改代码后更新数据库

Question

I had a class named feedback generated via database first approach

public partial class Feedback
{
    public Nullable<byte> OverallExperienceFb { get; set; }
    public Nullable<byte> FunFb { get; set; }
    public Nullable<byte> FoodFb { get; set; }
    public Nullable<byte> TravelFb { get; set; }
    public Nullable<byte> PlanningFb { get; set; }
    public Nullable<byte> MusicFb { get; set; }
    public Nullable<byte> PlaceFb { get; set; }
    public Nullable<byte> WeatherFb { get; set; }
    public Nullable<int> Paid { get; set; }
    public int ID{get; set;}
}

I later added a constraint of range 0-5 on overallFb as following:-

public partial class TravellerTripStatus
{
    [Range(0,5)]
    public Nullable<byte> OverallExperienceFb { get; set; }
}

This change is reflecting on the GUI such that the edit form won't allow to enter value out of the range but how to make this change reflect into database (such that a check contraint automatically gets added to overallFB field of table definition)?

When i try to generate database from model, no such constraint is enforced.

Answer 1

Adding constraints to a table is currently not possible with data annotations or fluid API. But the workaround is to issue a SQL command in your Configuration.cs file inside your Seed method:

db.Database.ExecuteSqlCommand("ALTER TABLE TravellerTripStatus ADD CONSTRAINT CK_TravellerTripStatus_OverallExperienceFb CHECK (OverallExperienceFb BETWEEN 0 AND 5)");