EF代码优先：流畅的API配置 - 如何在TPH中配置子类的属性？

Question

如果我在TPH配置中有一个基类和两个派生类，如何在流畅的API中配置派生类的标量属性（例如字符串的长度）？

实施例：     public enum PersonType {Employee，Manager}

public abstract class Person 
{ 
    public string FirstName {get; set;} 
    public string LastName {get; set;} 
} 

public class Employee : Person 
{ 
    public string Designation {get; set;} 
} 

public class Manager : Person 
{ 
    public string Division {get; set;} 
} 

//fluent api config 
internal class PersonConfig : EntityTypeConfiguration<Person>
{ 
    public PersonConfig() 
    { 
        Property(p => p.FirstName) .HasMaxLength(250); 
        Property(p => p.LastName) .HasMaxLength(250); 
        Map<Employee>(e => e.Requires(x => x.PersonType).HasValue()); 
        **//how to configure Designation ?** 
        Map<Manager>(m => m.Requires(y => y.PersonType).HasValue()); 
        **//how to configure Division ?** 
    } 
}

Answer 1

您可以按照配置常规实体的方式配置派生实体 - 使用单独的流畅配置，例如

internal class EmployeeConfig : EntityTypeConfiguration<Employee>
{ 
    public EmployeeConfig() 
    { 
        Property(e => e.Designation).HasMaxLength(250);
        // ... 
    } 
}

internal class ManagerConfig : EntityTypeConfiguration<Manager>
{ 
    public ManagerConfig() 
    { 
        Property(m => m.Division).HasMaxLength(250);
        // ... 
    } 
}