c#-具有接口的实体框架代码优先迁移

我正在尝试使用属性/注释方法(以接口作为属性类型)运行EF代码优先迁移.我们已经建立了带有接口的完整基础架构,并正在使用这些接口来实现具体的类并希望启用迁移. EF似乎并没有正确地关联外键关系.有什么办法可以纠正这个问题？

这是一个例子：

我有一个IStateProvince接口,如下所示：

 public interface IStateProvince
{

    string Abbreviation { get; set; }

    string Name { get; set; }

    ICountry Country { get; set; }

}

我也有一个ICountry接口,如下所示：

public interface ICountry
{

    string Name { get; set; }

    [MaxLength(2)]
    string TwoLetterIsoCode { get; set; }

    [MaxLength(3)]
    string ThreeLetterIsoCode { get; set; }

    int NumericIsoCode { get; set; }

    List<IStateProvince> StateProvinces { get; set; }
}

我创建了以下具体实现：

[Table("TypeData.Country")]
public class Country : BaseSqlEntity, ICountry
{

    [Required, MaxLength(250)]
    public string Name { get; set; }

    [Required]
    public string TwoLetterIsoCode { get; set; }

    [Required]
    public string ThreeLetterIsoCode { get; set; }

    public int NumericIsoCode { get; set; }

    public virtual List<IStateProvince> StateProvinces { get; set; }

}

州府如下：

[Table("TypeData.StateProvince")]
public class StateProvince : BaseSqlEntity, IStateProvince
{

    [Required, MaxLength(3)]
    public string Abbreviation { get; set; }

    [Required, MaxLength(250)]
    public string Name { get; set; }

    public Guid CountryId { get; set; }

    [ForeignKey("CountryId")]
    public virtual ICountry Country { get; set; }

}

您看到的BaseSqlEntity如下：

public class BaseSqlEntity
{
    [Key]
    public Guid Id { get; set; }

    public DateTime DateCreatedUtc { get; set; }

    public DateTime DateModifiedUtc { get; set; }

    public BaseSqlEntity()
    {
        DateCreatedUtc = DateModifiedUtc = DateTime.UtcNow;
        Id = Guid.NewGuid();
    }

}

我在上下文中添加了dbset,如下所示：

public DbSet<Country> Countries { get; set; }
public DbSet<StateProvince> StateProvinces { get; set; }

运行迁移后,我得到以下信息：

public override void Up()
    {
        CreateTable(
            "TypeData.Country",
            c => new
                {
                    Id = c.Guid(nullable: false),
                    Name = c.String(nullable: false, maxLength: 250),
                    TwoLetterIsoCode = c.String(nullable: false),
                    ThreeLetterIsoCode = c.String(nullable: false),
                    NumericIsoCode = c.Int(nullable: false),
                    DateCreatedUtc = c.DateTime(nullable: false),
                    DateModifiedUtc = c.DateTime(nullable: false),
                })
            .PrimaryKey(t => t.Id);

        CreateTable(
            "TypeData.StateProvince",
            c => new
                {
                    Id = c.Guid(nullable: false),
                    Abbreviation = c.String(nullable: false, maxLength: 3),
                    Name = c.String(nullable: false, maxLength: 250),
                    CountryId = c.Guid(nullable: false),
                    DateCreatedUtc = c.DateTime(nullable: false),
                    DateModifiedUtc = c.DateTime(nullable: false),
                })
            .PrimaryKey(t => t.Id);

    }

您将注意到,没有生成外键关系,因为它无法以某种方式将ICountry与其实现国家/地区关联起来.

如果我将类型从ICountry更改为Country并注释该界面,则它可以正常工作并正确生成关系.

有没有解决的办法？任何帮助将不胜感激.我们已经使用我们希望使用的接口构建了很多可重用的体系结构,但是看起来这可能是一个阻碍.

解决方法:

您仍然可以使用这些接口.
只需在下面的具体类中实现接口属性.

[Table("TypeData.Country")]
public class Country : BaseSqlEntity, ICountry
{

    [Required, MaxLength(250)]
    public string Name { get; set; }

    [Required]
    public string TwoLetterIsoCode { get; set; }

    [Required]
    public string ThreeLetterIsoCode { get; set; }

    public int NumericIsoCode { get; set; }

    public virtual List<StateProvince> StateProvinces { get; set; }

    List<IStateProvince> ICountry.StateProvinces
    {
        get
        {
            return StateProvinces.ToList<IStateProvince>();
        }

        set
        {
            StateProvinces = value.ToList().ConvertAll(o => (StateProvince)o);
        }
    }
}

和

[Table("TypeData.StateProvince")]
public class StateProvince : BaseSqlEntity, IStateProvince
{

    [Required, MaxLength(3)]
    public string Abbreviation { get; set; }

    [Required, MaxLength(250)]
    public string Name { get; set; }

    public Guid CountryId { get; set; }

    [ForeignKey("CountryId")]
    public virtual Country Country { get; set; }

    ICountry IStateProvince.Country
    {
        get
        {
            return Country;
        }

        set
        {
            Country = (Country)value;
        }
    }
}

希望这能解决您的问题.

标签：ef-migrations,c,entity-framework
来源： https://codeday.me/bug/20191027/1946276.html