Question

我尝试使用此模型在User和TeamMember之间建立0-1关系

public class User
    {
        [Key]
        public Guid Id { get; set; }

        public Guid? TeamMemberId { get; set; }

        public virtual TeamMember TeamMember { get; set; }
    }

    public partial class TeamMember
    {


        [Key]
        [Column(Order = 0)]
        public Guid TeamId { get; set; }

        [Key]
        [Column(Order = 1)]
        public Guid UserId { get; set; }

        public virtual MSUCTeam Team { get; set; }

        public virtual User User { get; set; }

    }

    public class Team
    {
        [Key]
        public Guid Id { get; set; }

        public virtual ICollection<TeamMember> TeamMembers { get; set; }
    }

要告诉EF关于这种关系的所有信息，我使用了如下的流利API

            modelBuilder.Entity<Team>()
            .HasMany(e => e.TeamMembers)
            .WithRequired(e => e.Team)
            .HasForeignKey(e => e.TeamId).WillCascadeOnDelete();

             modelBuilder.Entity<User>()
            .HasOptional(e => e.TeamMember)
            .WithRequired(e => e.User);

表格本身是在上下文中定义的

        public virtual DbSet<Team> Teams { get; set; }

        public virtual DbSet<TeamMembers> TeamMembers { get; set; }

这会在数据库中生成所需的表，但TeamMembers表有3列：

1）TeamId（Guid，非可空）：PK和FK链接到Team.Id. 2）UserId（Guid，non nullable）：PK。 3）User_Id（Guid，不可为空）：FK链接到User.Id

如何将UserId列作为链接到User表的PK和FK？在没有UserId和TeamId的情况下，我们不会成为TeamMember的参赛者，但我必须告诉EF错误的我想要它做什么。

Answer 1

我真的无法测试这个，但尝试设置外键注释

public partial class TeamMember
{
    [Key]
    [Column(Order = 0)]
    public Guid TeamId { get; set; }

    [Key]
    [Column(Order = 1)]
    public Guid UserId { get; set; }

    [ForeignKey("TeamId")]
    public virtual MSUCTeam Team { get; set; }

    [ForeignKey("UserId")]
    public virtual User User { get; set; }

}

Answer 2

使用它：

public class User
{
    [Key]
    public Guid Id { get; set; }

    public virtual TeamMember TeamMember { get; set; }
}

public partial class TeamMember
{
    [Key, ForeignKey("User")]
    public Guid Id{ get; set; }

    public virtual User User { get; set; }
}

protected override void OnModelCreating(DbModelBuilder modelBuilder)  
{  
    modelBuilder.Entity<TeamMember>()
                .HasRequired(p => p.User)
                .WithOptional(p => p.TeamMember);
}

有关拆分表的详细信息，请查看此link;

Entity Framework可选外键在依赖中创建冗余FK字段

2 个答案: