我正在尝试使用Attribute / annotations方法运行EF代码优先迁移,并将接口作为属性类型。我们使用接口构建了一个完整的基础架构,并使用它们来实现具体的类并希望启用迁移。 EF似乎没有正确关联外键关系。有没有办法纠正这个?
以下是一个例子:
我有一个IStateProvince接口如下:
public interface IStateProvince
{
string Abbreviation { get; set; }
string Name { get; set; }
ICountry Country { get; set; }
}
我还有一个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; }
}
我已经创建了具体的实现,如下所示:
[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; }
}
州政府如下:
[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dbsets,如下所示:
public DbSet<Country> Countries { get; set; }
public DbSet<StateProvince> StateProvinces { get; set; }
运行迁移后,我得到以下内容:
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);
}
正如您将注意到的,没有生成外键关系,因为它无法以某种方式将ICountry与其实现Country相关联。
如果我将类型从ICountry更改为Country并注释界面,它可以正常工作并正确生成关系。
有解决方法吗?任何帮助将非常感谢。我们使用我们希望使用的界面构建了大量可重用的体系结构,但似乎这可能是一个显示阻止。
答案 0 :(得分:4)
您仍然可以使用这些界面 只需要在具体类中实现接口属性,如下所示。
[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;
}
}
}
希望这可以解决您的问题。