在我的models目录中，我有以下代码
public class Post
{
// Each post will have an ID
public string Id { get; set; }
// Each Post must have a title
[Required]
[StringLength(50, ErrorMessage = "The {0} must be between {2} and {1} characters long.", MinimumLength = 5)]
[Display(Name = "Title")]
public string Title { get; set; }
// Each Post must have a short description
[Required]
[StringLength(250, ErrorMessage = "The {0} must be between {2} and {1} characters long.", MinimumLength = 20)]
[Display(Name = "Short Description")]
public string ShortDescription { get; set; }
// Each Post must have a body
[Required]
[StringLength(5000, ErrorMessage = "The {0} must be between {2} and {1} characters long.", MinimumLength = 500)]
[Display(Name = "Body")]
public string Body { get; set; }
// Each Post must have meta description to use in the meta tag
[Required]
[StringLength(25, ErrorMessage = "The {0} must be between {2} and {1} characters long.", MinimumLength = 5)]
[Display(Name = "Meta")]
public string Meta { get; set; }
// User friendly urls
[Required]
[Display(Name = "UrlSeo")]
public string UrlSeo { get; set; }
// A boolean to check if the post has been published
public bool Published { get; set; }
[DefaultValue(0)]
// Count of how many likes the post has
public int NetLikeCount { get; set; }
//DateTime when it was created
public DateTime PostedOn { get; set; }
//DateTime when it was modified
public DateTime? Modified { get; set; }
//Properties which define relationships between tables
public ICollection<Comment> Comments { get; set; }
public ICollection<Reply> Replies { get; set; }
public ICollection<PostCategory> PostCategories { get; set; }
public ICollection<PostTag> PostTags { get; set; }
public ICollection<PostVideo> PostVideos { get; set; }
public ICollection<PostLike> PostLikes { get; set; }
}
public class Comment
{
public string Id { get; set; }
public string PostId { get; set; }
public DateTime DateTime { get; set; }
public string UserName { get; set; }
[Required]
[StringLength(1000, ErrorMessage = "The {0} must be between {2} and {1} characters long.", MinimumLength = 25)]
[Display(Name = "Body")]
public string Body { get; set; }
[DefaultValue(0)]
public int NetLikeCount { get; set; }
[DefaultValue(false)]
public bool Deleted { get; set; }
public Post Post { get; set; }
public ICollection<Reply> Replies { get; set; }
public ICollection<CommentLike> CommentLikes { get; set; }
}
public class Reply
{
public string Id { get; set; }
public string PostId { get; set; }
public string CommentId { get; set; }
public string ParentReplyId { get; set; }
public DateTime DateTime { get; set; }
public string UserName { get; set; }
[Required]
[StringLength(1000, ErrorMessage = "The {0} must be between {2} and {1} characters long.", MinimumLength = 25)]
[Display(Name = "Body")]
public string Body { get; set; }
public bool Deleted { get; set; }
public Post Post { get; set; }
public Comment Comment { get; set; }
public ICollection<ReplyLike> ReplyLikes { get; set; }
}
public class PostCategory
{
[Key]
[Column(Order = 0)]
public string PostId { get; set; }
[Key]
[Column(Order = 1)]
public string CategoryId { get; set; }
public bool Checked { get; set; }
public Post Post { get; set; }
public Category Category { get; set; }
}
public class PostTag
{
[Key]
[Column(Order = 0)]
public string PostId { get; set; }
[Key]
[Column(Order = 1)]
public string TagId { get; set; }
public bool Checked { get; set; }
public Post Post { get; set; }
public Tag Tag { get; set; }
}
public class PostVideo
{
public string Id { get; set; }
[Required]
[Display(Name = "VideoUrl")]
[DataType(DataType.Url)]
public string VideoUrl { get; set; }
public string VideoThumbnail { get; set; }
public string PostId { get; set; }
public string VideoSiteName { get; set; }
public Post Post { get; set; }
}
public class PostLike
{
[Key]
public string PostId { get; set; }
public string UserName { get; set; }
public bool Like { get; set; }
public bool DisLike { get; set; }
public Post Post { get; set; }
}
public class Category
{
public string Id { get; set; }
[Required]
[Display(Name = "Name")]
public string Name { get; set; }
[Required]
[Display(Name = "UrlSeo")]
public string UrlSeo { get; set; }
[Required]
[StringLength(20, ErrorMessage = "The {0} must be between {2} and {1} characters long.", MinimumLength = 5)]
[Display(Name = "Description")]
public string Description { get; set; }
public bool Checked { get; set; }
public ICollection<PostCategory> PostCategories { get; set; }
}
public class CommentLike
{
[Key]
public string CommentId { get; set; }
public string UserName { get; set; }
public bool Like { get; set; }
public bool DisLike { get; set; }
public Comment Comment { get; set; }
}
public class ReplyLike
{
[Key]
public string ReplyId { get; set; }
public string UserName { get; set; }
public bool Like { get; set; }
public bool DisLike { get; set; }
public Reply Reply { get; set; }
}
public class Tag
{
public string Id { get; set; }
[Required]
[Display(Name = "Name")]
public string Name { get; set; }
[Required]
[StringLength(20, ErrorMessage = "The {0} must be between {2} and {1} characters long.", MinimumLength = 5)]
[Display(Name = "UrlSeo")]
public string UrlSeo { get; set; }
public bool Checked { get; set; }
public ICollection<PostTag> PostTags { get; set; }
}
所以这些是我试图添加迁移的数据模式
当我尝试添加此迁移时，它告诉我实体类型“Blog.Models.PostCategory”需要定义一个键。我该如何解决这个错误
答案 0 :(得分：1)
这是为您的类自动生成的迁移类，并在我的解决方案中正常工作，试一试：
public partial class Blog : DbMigration
{
public override void Up()
{
CreateTable(
"dbo.PostCategories",
c => new
{
PostId = c.String(nullable: false, maxLength: 128),
CategoryId = c.String(nullable: false, maxLength: 128),
Checked = c.Boolean(nullable: false),
})
.PrimaryKey(t => new { t.PostId, t.CategoryId })
.ForeignKey("dbo.Categories", t => t.CategoryId, cascadeDelete: true)
.ForeignKey("dbo.Posts", t => t.PostId, cascadeDelete: true)
.Index(t => t.PostId)
.Index(t => t.CategoryId);
CreateTable(
"dbo.Categories",
c => new
{
Id = c.String(nullable: false, maxLength: 128),
Name = c.String(nullable: false),
UrlSeo = c.String(nullable: false),
Description = c.String(nullable: false, maxLength: 20),
Checked = c.Boolean(nullable: false),
})
.PrimaryKey(t => t.Id);
CreateTable(
"dbo.Posts",
c => new
{
Id = c.String(nullable: false, maxLength: 128),
Title = c.String(nullable: false, maxLength: 50),
ShortDescription = c.String(nullable: false, maxLength: 250),
Body = c.String(nullable: false),
Meta = c.String(nullable: false, maxLength: 25),
UrlSeo = c.String(nullable: false),
Published = c.Boolean(nullable: false),
NetLikeCount = c.Int(nullable: false),
PostedOn = c.DateTime(nullable: false),
Modified = c.DateTime(),
})
.PrimaryKey(t => t.Id);
CreateTable(
"dbo.Comments",
c => new
{
Id = c.String(nullable: false, maxLength: 128),
PostId = c.String(maxLength: 128),
DateTime = c.DateTime(nullable: false),
UserName = c.String(),
Body = c.String(nullable: false, maxLength: 1000),
NetLikeCount = c.Int(nullable: false),
Deleted = c.Boolean(nullable: false),
})
.PrimaryKey(t => t.Id)
.ForeignKey("dbo.Posts", t => t.PostId)
.Index(t => t.PostId);
CreateTable(
"dbo.CommentLikes",
c => new
{
CommentId = c.String(nullable: false, maxLength: 128),
UserName = c.String(),
Like = c.Boolean(nullable: false),
DisLike = c.Boolean(nullable: false),
Comment_Id = c.String(maxLength: 128),
})
.PrimaryKey(t => t.CommentId)
.ForeignKey("dbo.Comments", t => t.Comment_Id)
.Index(t => t.Comment_Id);
CreateTable(
"dbo.Replies",
c => new
{
Id = c.String(nullable: false, maxLength: 128),
PostId = c.String(maxLength: 128),
CommentId = c.String(maxLength: 128),
ParentReplyId = c.String(),
DateTime = c.DateTime(nullable: false),
UserName = c.String(),
Body = c.String(nullable: false, maxLength: 1000),
Deleted = c.Boolean(nullable: false),
})
.PrimaryKey(t => t.Id)
.ForeignKey("dbo.Comments", t => t.CommentId)
.ForeignKey("dbo.Posts", t => t.PostId)
.Index(t => t.PostId)
.Index(t => t.CommentId);
CreateTable(
"dbo.ReplyLikes",
c => new
{
ReplyId = c.String(nullable: false, maxLength: 128),
UserName = c.String(),
Like = c.Boolean(nullable: false),
DisLike = c.Boolean(nullable: false),
Reply_Id = c.String(maxLength: 128),
})
.PrimaryKey(t => t.ReplyId)
.ForeignKey("dbo.Replies", t => t.Reply_Id)
.Index(t => t.Reply_Id);
CreateTable(
"dbo.PostLikes",
c => new
{
PostId = c.String(nullable: false, maxLength: 128),
UserName = c.String(),
Like = c.Boolean(nullable: false),
DisLike = c.Boolean(nullable: false),
Post_Id = c.String(maxLength: 128),
})
.PrimaryKey(t => t.PostId)
.ForeignKey("dbo.Posts", t => t.Post_Id)
.Index(t => t.Post_Id);
CreateTable(
"dbo.PostTags",
c => new
{
PostId = c.String(nullable: false, maxLength: 128),
TagId = c.String(nullable: false, maxLength: 128),
Checked = c.Boolean(nullable: false),
})
.PrimaryKey(t => new { t.PostId, t.TagId })
.ForeignKey("dbo.Posts", t => t.PostId, cascadeDelete: true)
.ForeignKey("dbo.Tags", t => t.TagId, cascadeDelete: true)
.Index(t => t.PostId)
.Index(t => t.TagId);
CreateTable(
"dbo.Tags",
c => new
{
Id = c.String(nullable: false, maxLength: 128),
Name = c.String(nullable: false),
UrlSeo = c.String(nullable: false, maxLength: 20),
Checked = c.Boolean(nullable: false),
})
.PrimaryKey(t => t.Id);
CreateTable(
"dbo.PostVideos",
c => new
{
Id = c.String(nullable: false, maxLength: 128),
VideoUrl = c.String(nullable: false),
VideoThumbnail = c.String(),
PostId = c.String(maxLength: 128),
VideoSiteName = c.String(),
})
.PrimaryKey(t => t.Id)
.ForeignKey("dbo.Posts", t => t.PostId)
.Index(t => t.PostId);
}
public override void Down()
{
DropForeignKey("dbo.PostVideos", "PostId", "dbo.Posts");
DropForeignKey("dbo.PostTags", "TagId", "dbo.Tags");
DropForeignKey("dbo.PostTags", "PostId", "dbo.Posts");
DropForeignKey("dbo.PostLikes", "Post_Id", "dbo.Posts");
DropForeignKey("dbo.PostCategories", "PostId", "dbo.Posts");
DropForeignKey("dbo.ReplyLikes", "Reply_Id", "dbo.Replies");
DropForeignKey("dbo.Replies", "PostId", "dbo.Posts");
DropForeignKey("dbo.Replies", "CommentId", "dbo.Comments");
DropForeignKey("dbo.Comments", "PostId", "dbo.Posts");
DropForeignKey("dbo.CommentLikes", "Comment_Id", "dbo.Comments");
DropForeignKey("dbo.PostCategories", "CategoryId", "dbo.Categories");
DropIndex("dbo.PostVideos", new[] { "PostId" });
DropIndex("dbo.PostTags", new[] { "TagId" });
DropIndex("dbo.PostTags", new[] { "PostId" });
DropIndex("dbo.PostLikes", new[] { "Post_Id" });
DropIndex("dbo.ReplyLikes", new[] { "Reply_Id" });
DropIndex("dbo.Replies", new[] { "CommentId" });
DropIndex("dbo.Replies", new[] { "PostId" });
DropIndex("dbo.CommentLikes", new[] { "Comment_Id" });
DropIndex("dbo.Comments", new[] { "PostId" });
DropIndex("dbo.PostCategories", new[] { "CategoryId" });
DropIndex("dbo.PostCategories", new[] { "PostId" });
DropTable("dbo.PostVideos");
DropTable("dbo.Tags");
DropTable("dbo.PostTags");
DropTable("dbo.PostLikes");
DropTable("dbo.ReplyLikes");
DropTable("dbo.Replies");
DropTable("dbo.CommentLikes");
DropTable("dbo.Comments");
DropTable("dbo.Posts");
DropTable("dbo.Categories");
DropTable("dbo.PostCategories");
}
}