Question

这是我想用实体框架映射的场景，从它看起来我相信它在SQL Server中是可能的，因此它可能在Entity Framework中是正确的吗？所以这里，

方案

操作由团队成员组成。两名团队成员很特别，他们是领导者和共同领导者。我希望这些直接附加到像这样的操作

public class Operation
{
    public int OperationId { get; set; }

    [ForeignKey("Leader")]
    public int LeaderId { get; set; }
    public TeamMember Leader { get; set; }

    [ForeignKey("CoLeader")]
    public int CoLeaderId { get; set; }
    public TeamMember CoLeader { get; set; }

    /// <summary>
    /// Everybody in the operation
    /// </summary>
    public List<TeamMember> Team { get; set; }
}

团队成员看起来像这样：

/// <summary>
/// A team member is specific for an operation, and is the linking table
/// between people and an operation
/// 
/// This table cannot be a composite key of OperationId and PersonId, 
/// as team members are created first and then the Person is assigned 
/// to be a team member.
/// </summary>
public class TeamMember
{
    public int TeamMemberId { get; set; }

    [ForeignKey("Operation")]
    public int OperationId { get; set; }

    public Operation Operation { get; set; }

    [ForeignKey("Person")]
    public int PersonId { get; set; }
    public Person Person { get; set; }
}

现在这几乎可以了。如果我从Operation中删除导航属性TeamMember，我会获得所需的数据库。但是使用导航属性我收到错误：

Unable to determine the principal end of the 'TeamMember_Operation'
relationship. Multiple added entities may have the same primary key.

所以现在有点狡猾的东西，你可以在查询teamMember.Operation.Leader.Operation.Leader等时这样做....但你无论如何都可以在数据库查询中这样做，所以我想这不是错误的原因。

问题

为什么要使用相同的主键添加多个实体，以及如何解决此问题。

（如果可能，会更喜欢数据注释）

多个添加的实体可能具有相同的主键，困难的映射方案

0 个答案: