实例解析继承体系重构及ORM映射

4. 对图2的ORM映射

4.1 单表继承体系

采用单表继承体系映射时，我们用一个AllInOne表包含所有实体的所有字段，并用一个FilterMark过滤标志，区分该条纪录的类型，注意只有所有的User，包括抽象的User和所有的UserGroup是可以查询的，其余接口仅仅用于概念抽象。

代码4

[Table(IsView=true)]
public interface IdentableEntity : IEntity
{
[PrimaryKey]
int Id { get; }
string Name { get; set; }
}

[Table(IsView=true)]
public interface Loginable : IEntity
{
string LoginId { get; set; }
}

[Table(IsView=true)]
public interface PasswordLoginable : Loginable
{
string Password { get; set; }
}

[Table(IsView = true)]
public interface PrivilegeAssignable
{
int PrivilegeOwnerId { get; set; }
}

[Table("AllInOne", AdditionalWhere = "FilterMark <= 20", IsView = true)]
public interface User : IdentableEntity, PrivilegeAssignable
{
}

[Table("AllInOne", AdditionalInsert = "FilterMark = 1", AdditionalWhere = "FilterMark = 1")]
public interface LocalUser : User, PasswordLoginable
{
}

[Table("AllInOne", AdditionalInsert="FilterMark = 2", AdditionalWhere="FilterMark = 2")]
public interface AgentUser : User, Loginable
{
}

[Table("AllInOne", AdditionalInsert = "FilterMark = 3", AdditionalWhere = "FilterMark = 3")]
public interface GhostUser : User
{
}

[Table("AllInOne", AdditionalInsert = "FilterMark = 21", AdditionalWhere = "FilterMark = 21")]
public interface UserGroup : IdentableEntity, PrivilegeAssignable
{
string Comment { get; set; }
}