使用多对多关系保存时的外键冲突EF6

Question

I have three tables:

CREATE TABLE [dbo].[Committees] (
    [committee_id]          INT             IDENTITY (1, 1) NOT NULL,
    [Committee_name]        NVARCHAR (128)  NULL,
    [Committee_email]       NVARCHAR (128)  NULL,
    [Committee_inactive]    INT             NULL,
    [Committee_type]        NVARCHAR (50)   NULL,
    [Committee_description] NVARCHAR (1024) NULL,
    [Committee_chair_id]    INT             NOT NULL,
    [Committee_sponsor_id]  INT             NOT NULL,
    [Committee_end_date]    DATETIME2 (7)   NULL,
    [bMembershipOpen]       BIT             CONSTRAINT [DF_Committees_bMembershipOpen] DEFAULT ((0)) NOT NULL,
    CONSTRAINT [PK_Committees] PRIMARY KEY CLUSTERED ([committee_id] ASC),
    CONSTRAINT [FK_CommitteesChair_ToPersons] FOREIGN KEY ([Committee_chair_id]) REFERENCES [dbo].[Persons] ([Id]),
    CONSTRAINT [FK_CommitteesSponsor_ToPersons] FOREIGN KEY ([Committee_sponsor_id]) REFERENCES [dbo].[Persons] ([Id])
);

CREATE TABLE [dbo].[Persons] (
    [Id]    INT            IDENTITY (1, 1) NOT NULL,
    [Name]  NVARCHAR (128) NULL,
    [Email] NVARCHAR (128) NULL,
    CONSTRAINT [PK_Persons] PRIMARY KEY CLUSTERED ([Id] ASC)
);

and

CREATE TABLE [dbo].[CommitteeMembers] (
    [CommitteeId] INT NOT NULL,
    [PersonId]    INT NOT NULL,
    PRIMARY KEY CLUSTERED ([CommitteeId] ASC, [PersonId] ASC),
    CONSTRAINT [FK_CommitteeMembers_ToCommittee] FOREIGN KEY ([CommitteeId]) REFERENCES [dbo].[Committees] ([committee_id]),
    CONSTRAINT [FK_CommitteeMembers_ToPerson] FOREIGN KEY ([PersonId]) REFERENCES [dbo].[Persons] ([Id])
);

I have two classes associated with Committees and Persons

 public class Committee {

        [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
        [Column("committee_id")]
        [Key]
        public int Id { get; set; }

        [Column("Committee_chair_id")]
        [ForeignKey("Chairman")]
        [Required(ErrorMessage = "Committee must have a Chairman")]
        public int ChairmanId { get; set; }

        [Column("Committee_sponsor_id")]
        [ForeignKey("Sponsor")]
        [Required(ErrorMessage = "Committee must have a Sponsor")]
        public int SponsorId { get; set; }

        [Column("Committee_name")]
        [MinLength(3, ErrorMessage = "Committee Name must be at least 3 characters long")]
        [MaxLength(128, ErrorMessage = "Committee Name cannot be longer than 128 characters")]
        [Required(ErrorMessage = "Committee must have a name")]
        public string Name { get; set; }

        [Column("Committee_email")]
        [EmailAddress]
        [Required(ErrorMessage = "Committee must have an Email Address")]
        public string Email { get; set; }

        [Column("Committee_inactive")]
        public int? Inactive { get; set; }

        [Column("Committee_type")]
        [Required(ErrorMessage = "Committee must have a Type")]
        public string Type { get; set; }

        [Column("Committee_description")]
        [MaxLength(1000, ErrorMessage = "Committee Name cannot be longer than 1000 characters")]
        public string Description { get; set; }

        [Column("Committee_end_date")]
        public DateTime? EndDate { get; set; }

        [Column("bMembershipOpen")]
        [DefaultValue(false)]
        [Display(Name="Membership Open")]
        [Required]
        public bool MembershipOpen { get; set; }

        public Person Chairman { get; set; }

        public Person Sponsor { get; set; }

        public virtual ICollection<Person> Members { get; set; }

        public virtual ICollection<Note> Notes { get; set; }  

        public virtual ICollection<NextStep> NextSteps { get; set; } 

        public virtual ICollection<Outcome> Outcomes { get; set; } 

        public virtual ICollection<Video> Videos { get; set; } 
    }

and

public class Person {

    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public int Id { get; set; }

    [Required(ErrorMessage = "You must specify a name")]
    [MaxLength(128, ErrorMessage = "Name cannot be longer than 128 characters")]
    public string Name { get; set; }

    [EmailAddress]
    [MaxLength(128, ErrorMessage = "Email Address cannot be longer than 128 characters")]
    public string Email { get; set; }

    public virtual ICollection<Committee> Committees { get; set; } 
}

and I have the following in my DbContext

protected override void OnModelCreating(DbModelBuilder modelBuilder) { base.OnModelCreating(modelBuilder);

    modelBuilder.Entity<Committee>()
        .HasMany(c => c.Members)
        .WithMany(m => m.Committees)
        .Map(m=> {
            m.ToTable("CommitteeMembers");
            m.MapLeftKey("PersonId");
            m.MapRightKey("CommitteeId");
        });

    modelBuilder.Entity<Committee>()
        .HasMany(c => c.Notes)
        .WithRequired(n => n.Committee);

    modelBuilder.Entity<Committee>()
        .HasMany(c => c.NextSteps)
        .WithRequired(n => n.Committee);

    modelBuilder.Entity<Committee>()
        .HasMany(c => c.Outcomes)
        .WithRequired(o => o.Committee);

    modelBuilder.Entity<Committee>()
        .HasMany(c => c.Videos)
        .WithRequired(v => v.Committee);

    modelBuilder.Entity<Committee>()
        .HasRequired(c => c.Chairman);

    modelBuilder.Entity<Committee>()
        .HasRequired(c => c.Sponsor);

    modelBuilder.Entity<Person>()
        .Map(t => t.ToTable("Persons"));
}

All of my navigation properties work on my models except Committee.Members and Person.Committees. Whenever I try to save the DbContext after adding a Person to a Committee or a Committee to a Person I get an error like the following:

The INSERT statement conflicted with the FOREIGN KEY constraint "FK_CommitteeMembers_ToCommittee". The conflict occurred in database "EquipNetCommitteeDb", table "dbo.Committees", column 'committee_id'. The statement has been terminated.

Does anyone have any idea what I am doing wrong? This should work. I have done it many times before and I think I just need another set of eyes on it.

Answer 1

So it looks like Entity Framework did not like that I had already created Foreign Keys in the CommitteeMembers table. Once I removed those and let Entity Framework manage the relationships it worked. I'm not sure if this is how it is supposed to work though. If anyone knows anything about why I could not specify foreign keys in the table definition I would be curious to know the answer.