Fluent API - 一对多关系答案

【问题标题】：Fluent API - One 2 Many RelationshipFluent API - 一对多关系
【发布时间】：2016-10-20 11:09:42
【问题描述】：

我有两个实体，即员工和公司。这两者都可以有一个或多个地址。 由于 Guid 始终是唯一的，所以我想在 Employee 和 Company 中使用 Guid 作为 Address 中的外键。
也就是说，员工的地址中可以有多个条目，员工的 Guid 将在地址的 Guid 字段中。
同样，一家公司也可以有多个地址。公司的 Guid 将在地址的 Guid 中。

您能帮我如何使用 Fluent API 配置黑白 Employee-Address 和 Company-Address 关系

public class Employee
{
    public int EmployeeId;
    public Guid Guid;
    .
    .
    .
    public ICollection<Address> Addresses;
}

public class Company
{
    public int CompanyId;
    public Guid Guid;
    .
    .
    .
    public ICollection<Address> Addresses;
}

public class Address
{
    public int AddressId
    public Guid Guid; // Guid from Employee or Company
    .
    .
    . // Should here be Navigation to Employee/Company as well?


}

【问题讨论】：

标签： c# entity-framework ef-fluent-api

【解决方案1】：

我不确定我是否理解您的问题。你想要这样两个简单的 1:N 关系吗？：

Emplyee 1:N Adress
Company 1:N Adress

如果是这种情况，你应该有这个模型：

public class Employee
{
    public int EmployeeId { get; set; };
    // ...
    public virutal ICollection<Address> Addresses { get; set; };
}

public class Company
{
    public int CompanyId { get; set; };
    // ...
    public ICollection<Address> Addresses { get; set; };
}

public class Address
{
    public int AddressId { get; set; };
    public int? EmployeeId { get; set; };
    public int? CompanyId { get; set; };
    // ...
    public virtual Employee Employee { get; set; };
    public virtual Company Company { get; set; };
}

【讨论】：

【解决方案2】：

设置您的实体，例如

public class Employee
{
    //no need of following line. just use the GUID as Employee id
    //public int EmployeeId;  
    public Guid EmployeeId;
    .
    .
    .
    public ICollection<Address> Addresses;
}

public class Company
{
    public int CompanyId;//no need of this line, use guid as company id
    public Guid CompanyId;
    .
    .
    .
    public ICollection<Address> Addresses;
}

public class Address
{
    public int AddressId
    public Guid OwnerId; // Guid from Employee or Company
    .
    .
    //don't add Navigation to Employee/Company


}

然后在 fluent API 中，执行slauma 建议here 的操作。

modelBuilder.Entity<Company>()
.HasMany(c => c.Addresses)
.WithRequired()
.HasForeignKey(a => a.OwnerId);

modelBuilder.Entity<Employee>()
.HasMany(c => c.Addresses)
.WithRequired()
.HasForeignKey(a => a.OwnerId);

【讨论】：