c# - 外键问题(将实体种子添加到 'Comment' 并指定外键值 {'DocumentId' }。)EF

Question

我有数据类初始化器

public static class ModelBuilderExtention
{
    public static void Seed(this ModelBuilder modelBuilder)
    {
        List<Document> documents = new List<Document>()
        {
            new Document()
            {
                Id = 1,
                Title = "Top Cat! The most effectual ",
                Date = DateTime.Now.AddDays(-7),
                UserId = "1",
                FileLink = "https://sf-applications.s3.amazonaws.com/Bear/wallpapers/05/july-2020-wallpaper_desktop-3840x1600.png",
                ShortDescription = "Top Cat! Who’s intellectual close friends get to " +
                "call him T.C., providing it’s with dignity. " +
                "Top Cat! The indisputable leader of the gang. He’s the" +
                " boss, he’s a pip, he’s the championship. " +
                "He’s the most tip top, Top Cat.",
                Tags = new List<Tag>() {
                new Tag(){ DocumentId = 1, Id = 1, TagName ="Important"},
                new Tag(){ DocumentId = 1, Id = 2, TagName ="Cat"}
                },
                Comments = new List<Comment>() {
                new Comment(){
                Id = 1,
                Date = DateTime.Now.AddDays(-6),
                DocumentId = 1,
                UserId = "1",
                Content = "Ulysses, Ulysses — Soaring through all the" +
                " galaxies. In search of Earth, flying in to the night" +
                ". Ulysses, Ulysses — Fighting evil and tyranny, with " +
                "all his power, and with all of his might. "
                },
                new Comment(){
                Id = 2,
                Date = DateTime.Now.AddDays(-5),
                DocumentId = 1,
                UserId = "1",
                Content = "Ulysses — no-one else can do the things you do" +
                ". Ulysses — like a bolt of thunder from the blue. Ulysses " +
                "— always fighting all the evil forces bringing peace and justice to all."
                } }
            },
            new Document()
            {
                Id = 2,
                Title = "I never spend much time in school but",
                Date = DateTime.Now.AddDays(-5),
                UserId = "1",
                FileLink = "https://cdn.wallpaperhub.app/cloudcache/1/b/5/8/e/f/1b58ef6e3d36a42e01992accf5c52d6eea244353.jpg",
                ShortDescription = "I taught ladies plenty. It’s true I hire my body out for pay," +
                " hey hey. I’ve gotten burned over Cheryl Tiegs, blown up for Raquel Welch." +
                " But when I end up in the hay it’s only hay, hey hey. I might jump an open " +
                "drawbridge, or Tarzan from a vine.",
                Tags = new List<Tag>() {
                new Tag(){ DocumentId = 2, Id = 3, TagName ="Important"},
                new Tag(){ DocumentId = 2, Id = 4, TagName ="Plenty"}
                },
                Comments = new List<Comment>() {
                new Comment(){
                Id = 3,
                Date = DateTime.Now.AddDays(-5),
                DocumentId = 2,
                UserId = "1",
                Content = "Cause I’m the unknown stuntman that makes Eastwood look so fine."
                },
                new Comment(){
                Id = 4,
                Date = DateTime.Now.AddDays(-4),
                DocumentId = 2,
                UserId = "1",
                Content = "One for all and all for one, Muskehounds are always" +
                " ready. One for all and all for one, helping everybody. "
                } }
            },
            new Document()
            {
                Id = 3,
                Title = "One for all and all for one, it’s a pretty story.Sharing everything with fun, that’s the way to be",
                Date = DateTime.Now.AddDays(-4),
                UserId = "1",
                FileLink = "https://i.pinimg.com/originals/f7/ae/e8/f7aee8753832af613b63e51d5f07011a.jpg",
                ShortDescription = "One for all and all for one, Muskehounds are always ready. " +
                "One for all and all for one, helping everybody.",
                Tags = new List<Tag>() {
                new Tag(){ DocumentId = 3, Id = 5, TagName ="Important"},
                new Tag(){ DocumentId = 3, Id = 6, TagName ="Muskehounds"}
                },
                Comments = new List<Comment>() {
                new Comment(){
                Id = 5,
                Date = DateTime.Now.AddDays(-3),
                DocumentId = 3,
                UserId = "1",
                Content = "I never spend much time in school but I taught ladies plenty."
                },
                new Comment(){
                Id = 6,
                Date = DateTime.Now.AddDays(-3),
                DocumentId = 3,
                UserId = "1",
                Content = "It’s true I hire my body out for pay, hey hey."
                } }
            }
        };
        List<AccessRules> accessRules = new List<AccessRules>()
        {
            new AccessRules()
           {
               Id = 1,
               DocumentId = 1,
               DocumentLink = "Link to document",
               IsPublic = true
           },
            new AccessRules()
            {
                Id = 2,
                DocumentId = 2,
                DocumentLink = "Link to document",
                IsPublic = true
            },
            new AccessRules()
             {
                 Id = 3,
                 DocumentId = 3,
                 DocumentLink = "Link to document",
                 IsPublic = true
             }
        };

        foreach (var document in documents)
        {
            document.AccessRulesId = accessRules[document.Id - 1].Id;
        }

        modelBuilder.Entity<AccessRules>().HasData(accessRules);
          
        modelBuilder.Entity<Document>().HasData(documents);
    }
}

并且有 2 个主要实体文档

public class Document : BaseClass
{
    public string Title { get; set; }
    public DateTime Date { get; set; }
    public string ShortDescription { get; set; }
    public string FileLink { get; set; }
    public List<Tag> Tags { get; set; }
    public List<Comment> Comments { get; set; }
    [NotMapped]
    public AccessRules AccessRules { get; set; }
    [ForeignKey("AccessRules")]
    public int AccessRulesId { get; set; }
    public string UserId { get; set; }
}

和访问规则

public class AccessRules : BaseClass
{
    [NotMapped]
    public Document Document { get; set; }
    [ForeignKey("DocumentId")]
    public int DocumentId { get; set; }
    public string DocumentLink { get; set; }
    public bool IsPublic { get; set; }
}

我得到了这个错误

The seed entity for entity type 'Document' cannot be added because it has the navigation 'Comments' set. To seed relationships, add the entity seed to 'Comment' and specify the foreign key values {'DocumentId'}.

Consider using 'DbContextOptionsBuilder.EnableSensitiveDataLogging' to see the involved property values.

我必须如何更改实体才能使它们工作？

Answer 1

似乎为了通过多对多关系播种您的数据，您必须像这样使用 ModelBuilder 的流畅 API (from comment on EntityFramewor.Docs repo):

            modelBuilder.Entity<Post>()
                .HasMany(p => p.Tags)
                .WithMany(t => t.Posts)
                .UsingEntity<Dictionary<string, object>>(
                    "PostTag",
                    r => r.HasOne<Tag>().WithMany().HasForeignKey("TagId"),
                    l => l.HasOne<Post>().WithMany().HasForeignKey("PostId"),
                    je =>
                    {
                        je.HasKey("PostId", "TagId");
                        je.HasData(
                            new { PostId = 1, TagId = "general" },
                            new { PostId = 1, TagId = "informative" },
                            new { PostId = 2, TagId = "classic" },
                            new { PostId = 3, TagId = "opinion" },
                            new { PostId = 4, TagId = "opinion" },
                            new { PostId = 4, TagId = "informative" });
                    });

它不是很直观，也很难编写，但它似乎确实允许您在 EF 数据库中植入许多:许多关系。