Entity framework 无法为EF Core创建与SQLite提供程序的多对多关系

我现在正在试用EF Core，并决定试用SQLite作为一个提供者。我在互联网上遵循了一些指示，也考虑了stackoverflow的提要。不知何故，我没有创建多对多表

以下是我的DbContext文件的外观：

public class BloggingContext : DbContext
    {
        public DbSet<Blog> Blogs { get; set; }
        public DbSet<Post> Posts { get; set; }
        public DbSet<User> Users { get; set; }
        public DbSet<Group> Groups { get; set; }

        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
        {
            optionsBuilder.UseSqlite("Filename=./Blogging.db");
        }

        protected override void OnModelCreating(ModelBuilder modelBuilder)
        {
            modelBuilder.Entity<UserGroup>().HasKey(x => new { x.UserId, x.GroupId });

            modelBuilder.Entity<UserGroup>()
                .HasOne(pc => pc.User)
                .WithMany(p => p.UserGroups)
                .HasForeignKey(pc => pc.UserId);

            modelBuilder.Entity<UserGroup>()
                .HasOne(pc => pc.Group)
                .WithMany(c => c.UserGroups)
                .HasForeignKey(pc => pc.GroupId);
        }
    }

    public class Blog
    {
        public int BlogId { get; set; }
        public string Url { get; set; }

        public List<Post> Posts { get; set; }
    }

    public class Post
    {
        public int PostId { get; set; }
        public string Title { get; set; }
        public string Content { get; set; }

        public int MadeBy { get; set; }

        public int BlogId { get; set; }
        public Blog Blog { get; set; }
    }

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

        public ICollection<UserGroup> UserGroups { get; set; }
    }

    public class Group
    {
        [Key]
        public int Id { get; set; }

        public ICollection<UserGroup> UserGroups { get; set; }
    }

    // Needed for many-to-many https://stackoverflow.com/questions/29442493/how-to-create-a-many-to-many-relationship-with-latest-nightly-builds-of-ef-core
    public class UserGroup
    {
        [ForeignKey("User")]
        public int UserId { get; set; }
        public User User { get; set; }

        [ForeignKey("Group")]
        public int GroupId { get; set; }
        public Group Group { get; set; }
    }

如您所见，这些表似乎是创建的，但当我使用Firefox的db管理器打开db文件时，我只能看到创建的帖子和博客表

---

如何修复此问题？

目前，您必须自己创建多对多表：

---

它在未来版本的路线图中：

你这么说是什么意思？我必须手动更新我的迁移文件还是什么？

$ dotnet ef database update
Project ConsoleApp.SQLiteVS (.NETCoreApp,Version=v1.1) was previously compiled. Skipping compilation.
Executed DbCommand (4ms) [Parameters=[], CommandType='Text', CommandTimeout='30']
PRAGMA foreign_keys=ON;
Executed DbCommand (0ms) [Parameters=[], CommandType='Text', CommandTimeout='30']
PRAGMA foreign_keys=ON;
Executed DbCommand (35ms) [Parameters=[], CommandType='Text', CommandTimeout='30']
CREATE TABLE "__EFMigrationsHistory" (
    "MigrationId" TEXT NOT NULL CONSTRAINT "PK___EFMigrationsHistory" PRIMARY KEY,
    "ProductVersion" TEXT NOT NULL
);
Executed DbCommand (0ms) [Parameters=[], CommandType='Text', CommandTimeout='30']
PRAGMA foreign_keys=ON;
Executed DbCommand (0ms) [Parameters=[], CommandType='Text', CommandTimeout='30']
PRAGMA foreign_keys=ON;
Executed DbCommand (2ms) [Parameters=[], CommandType='Text', CommandTimeout='30']
SELECT COUNT(*) FROM "sqlite_master" WHERE "name" = '__EFMigrationsHistory' AND "type" = 'table';
Executed DbCommand (0ms) [Parameters=[], CommandType='Text', CommandTimeout='30']
PRAGMA foreign_keys=ON;
Executed DbCommand (0ms) [Parameters=[], CommandType='Text', CommandTimeout='30']
SELECT "MigrationId", "ProductVersion"
FROM "__EFMigrationsHistory"
ORDER BY "MigrationId";
Applying migration '20170117155520_MyFirstMigration'.
Executed DbCommand (0ms) [Parameters=[], CommandType='Text', CommandTimeout='30']
PRAGMA foreign_keys=ON;
Executed DbCommand (3ms) [Parameters=[], CommandType='Text', CommandTimeout='30']
CREATE TABLE "Blogs" (
    "BlogId" INTEGER NOT NULL CONSTRAINT "PK_Blogs" PRIMARY KEY AUTOINCREMENT,
    "Url" TEXT
);
Executed DbCommand (0ms) [Parameters=[], CommandType='Text', CommandTimeout='30']
CREATE TABLE "Groups" (
    "Id" INTEGER NOT NULL CONSTRAINT "PK_Groups" PRIMARY KEY AUTOINCREMENT
);
Executed DbCommand (0ms) [Parameters=[], CommandType='Text', CommandTimeout='30']
CREATE TABLE "Users" (
    "Id" INTEGER NOT NULL CONSTRAINT "PK_Users" PRIMARY KEY AUTOINCREMENT
);
Executed DbCommand (0ms) [Parameters=[], CommandType='Text', CommandTimeout='30']
CREATE TABLE "Posts" (
    "PostId" INTEGER NOT NULL CONSTRAINT "PK_Posts" PRIMARY KEY AUTOINCREMENT,
    "BlogId" INTEGER NOT NULL,
    "Content" TEXT,
    "MadeBy" INTEGER NOT NULL,
    "Title" TEXT,
    CONSTRAINT "FK_Posts_Blogs_BlogId" FOREIGN KEY ("BlogId") REFERENCES "Blogs" ("BlogId") ON DELETE CASCADE
);
Executed DbCommand (0ms) [Parameters=[], CommandType='Text', CommandTimeout='30']
CREATE TABLE "UserGroup" (
    "UserId" INTEGER NOT NULL,
    "GroupId" INTEGER NOT NULL,
    CONSTRAINT "PK_UserGroup" PRIMARY KEY ("UserId", "GroupId"),
    CONSTRAINT "FK_UserGroup_Groups_GroupId" FOREIGN KEY ("GroupId") REFERENCES "Groups" ("Id") ON DELETE CASCADE,
    CONSTRAINT "FK_UserGroup_Users_UserId" FOREIGN KEY ("UserId") REFERENCES "Users" ("Id") ON DELETE CASCADE
);
Executed DbCommand (0ms) [Parameters=[], CommandType='Text', CommandTimeout='30']
CREATE INDEX "IX_Posts_BlogId" ON "Posts" ("BlogId");
Executed DbCommand (0ms) [Parameters=[], CommandType='Text', CommandTimeout='30']
CREATE INDEX "IX_UserGroup_GroupId" ON "UserGroup" ("GroupId");
Executed DbCommand (0ms) [Parameters=[], CommandType='Text', CommandTimeout='30']
INSERT INTO "__EFMigrationsHistory" ("MigrationId", "ProductVersion")
VALUES ('20170117155520_MyFirstMigration', '1.1.0-rtm-22752');
Done.