在 EF Core 的 Code-First 中运行 Add-Migration 时出现错误。

huangapple
go评论106阅读模式
英文:

Get error when running Add-Migration in EF Core code-first

问题

我经常在互联网上搜索并向ChatGPT提问，但是我找不到答案。当我运行add-migration时，出现了错误：

无法从实体类型DataLayer.Models.QuizModel (Dictionary<string, object>)中删除属性quizType，因为它在外键{ 'quizType' }上被使用。在删除属性之前，必须删除或重新定义所有包含的外键。

但是我没有删除任何东西，我认为错误是错误的。这是我的quiz上下文和模型：

  1. namespace DataLayer.Models
  2. { 
  3.     public class QuizType
  4.     {
  5.         [Key]
  6.         [Required]
  7.         public int quizType { get; set; }
  9.         [MaxLength(150)]
  10.         public string QuizTitle { get; set; }
  12.         public QuizModel quizModel { get; set; }
  13.     }
  14. }

UserModel:

  1. namespace DataLayer.Models
  2. {
  3.     public class UserModel
  4.     {
  5.         [Key]
  6.         [Required]
  7.         public int UserID { get; set; }
  9.         [Required]
  10.         [MaxLength(300)]
  11.         public string UserName { get; set; }
  13.         [Required]
  14.         [MaxLength(300)]
  15.         public string Password { get; set; }
  17.         [AllowNull]
  18.         [MaxLength(150)]
  19.         public string Role { get; set; }
  21.         public ICollection<QuizModel> quizes { get; set; }
  22.     }
  23. }

QuizModel:

  1. namespace DataLayer.Models
  2. {
  3.     public class QuizModel
  4.     {
  5.         [Key]
  6.         [Required]
  7.         public int QuizID { get; set; }
  9.         [Required]
  10.         [MaxLength(150)]
  11.         public string QuizName { get; set; }
  13.         [Required]
  14.         [MaxLength(300)]
  15.         public string Categories { get; set; }
  17.         [Required]
  18.         public int QuestionCount { get; set; }
  20.         [Required]
  21.         public int QuizType { get; set; }
  23.         [ForeignKey("QuizType")]
  24.         public QuizType quizType { get; set; }
  26.         [Required]
  27.         [ForeignKey("User")]
  28.         public int UserID { get; set; }
  30.         public UserModel User { get; set; }
  32.         public ICollection<QuestionModel> Questions { get; set; }
  33.     }
  34. }

QuestionModel:

  1. namespace DataLayer.Models
  2. {
  3.     public class QuestionModel
  4.     {
  5.         [Key]
  6.         [Required]
  7.         public int QuestionID { get; set; }
  9.         [Required]
  10.         [MaxLength(400)]
  11.         public string QuestionText { get; set; }
  13.         [Required]
  14.         public int QuizType{ get; set; }
  16.         [ForeignKey(name:"quiz")]
  17.         public int QuizID { get; set; }
  19.         public QuizModel quiz { get; set; } 
  21.         public AnswerModel Answer { get; set; }
  23.         public ICollection<AnswerOption> Options { get; set; }
  24.     }
  25. }

AnswerModel和AnswerOption类：

  1. namespace DataLayer.Models
  2. {
  3.     public class AnswerModel
  4.     {
  5.         [Key]
  6.         [Required]
  7.         public int AnswerID { get; set; }
  9.         [Required]
  10.         [MaxLength(300)]
  11.         public string AnswerText { get; set; }
  13.         [Required]
  14.         [ForeignKey(name: "Question")]
  15.         public int QuestionID { get; set; }
  17.         public QuestionModel Question { get; set; }
  19.         [Required]
  20.         public bool AnswerValidation { get; set; }
  21.     }
  23.     public class AnswerOption
  24.     {
  25.         [Key]
  26.         [Required]
  27.         public int OptionID { get; set; }
  29.         [Required]
  30.         [MaxLength(300)]
  31.         public string OptionText { get; set; }
  33.         [Required]
  34.         public bool AnswerValidation { get; set; }
  36.         [Required]
  37.         [ForeignKey(name: "questionModel")]
  38.         public int QuestionID { get; set; }
  40.         public QuestionModel QuestionModel { get; set; }
  41.     }
  42. }
英文:

I search internet a lot and ask question form chatgpt a lot, too, but I can't find my answer. I got error when I run add-migration:

> The property 'quizType' cannot be removed from entity type 'DataLayer.Models.QuizModel (Dictionary<string, object>)' because it is being used in the foreign key {'quizType'} on 'DataLayer.Models.QuizModel (Dictionary<string, object>)'. All containing foreign keys must be removed or redefined before the property can be removed.

But I don't removed anything I think the error is wrong this is my quiz context and my model:

  1. namespace DataLayer.Models
  2. { 
  3.     public class QuizType
  4.     {
  5.         [Key]
  6.         [Required]
  7.         public int quizType { get; set; }
  9.         [MaxLength(150)]
  10.         public string QuizTitle { get; set; }
  12.         public QuizModel quizModel { get; set; }
  13.     }
  14. }

UserModel:

  1. namespace DataLayer.Models
  2. {
  3.     public class UserModel
  4.     {
  5.         [Key]
  6.         [Required]
  7.         public int UserID { get; set; }
  9.         [Required]
  10.         [MaxLength(300)]
  11.         public string UserName { get; set; }
  13.         [Required]
  14.         [MaxLength(300)]
  15.         public string Password { get; set; }
  17.         [AllowNull]
  18.         [MaxLength(150)]
  19.         public string Role { get; set; }
  21.         public ICollection&lt;QuizModel&gt; quizes { get; set; }
  22.     }
  23. }

QuizModel:

  1. namespace DataLayer.Models
  2. {
  3.     public class QuizModel
  4.     {
  5.         [Key]
  6.         [Required]
  7.         public int QuizID { get; set; }
  9.         [Required]
  10.         [MaxLength(150)]
  11.         public string QuizName { get; set; }
  13.         [Required]
  14.         [MaxLength(300)]
  15.         public string Categories { get; set; }
  17.         [Required]
  18.         public int QuestionCount { get; set; }
  20.         [Required]
  21.         public int QuizType { get; set; }
  23.         [ForeignKey(&quot;QuizType&quot;)]
  24.         public QuizType quizType { get; set; }
  26.         [Required]
  27.         [ForeignKey(&quot;User&quot;)]
  28.         public int UserID { get; set; }
  30.         public UserModel User { get; set; }
  32.         public ICollection&lt;QuestionModel&gt; Questions { get; set; }
  33.     }
  34. }

QuestionModel:

  1. namespace DataLayer.Models
  2. {
  3.     public class QuestionModel
  4.     {
  5.         [Key]
  6.         [Required]
  7.         public int QuestionID { get; set; }
  9.         [Required]
  10.         [MaxLength(400)]
  11.         public string QuestionText { get; set; }
  13.         [Required]
  14.         public int QuizType{ get; set; }
  16.         [ForeignKey(name:&quot;quiz&quot;)]
  17.         public int QuizID { get; set; }
  19.         public QuizModel quiz { get; set; } 
  21.         public AnswerModel Answer { get; set; }
  23.         public ICollection&lt;AnswerOption&gt; Oprtions { get; set; }
  24.     }
  25. }

AnswerModel and AnswerOption classes:

  1. namespace DataLayer.Models
  2. {
  3.     public class AnswerModel
  4.     {
  5.         [Key]
  6.         [Required]
  7.         public int AnswerID { get; set; }
  9.         [Required]
  10.         [MaxLength(300)]
  11.         public string Answertxt { get; set; }
  13.         [Required]
  14.         [ForeignKey(name: &quot;Question&quot;)]
  15.         public int QuestionID { get; set; }
  17.         public QuestionModel Question { get; set; }
  19.         [Required]
  20.         public bool AnswerValidation { get; set; }
  21.     }
  23.     public class AnswerOption
  24.     {
  25.         [Key]
  26.         [Required]
  27.         public int OptionID { get; set; }
  29.         [Required]
  30.         [MaxLength(300)]
  31.         public string Optiontxt { get; set; }
  33.         [Required]
  34.         public bool answerValidation { get; set; }
  36.         [Required]
  37.         [ForeignKey(name: &quot;questionModel&quot;)]
  38.         public int QuestionID { get; set; }
  40.         public QuestionModel questionModel { get; set; }
  41.     }
  42. }

答案1

得分: 0

你正在为"QuizType"类的主键使用错误的名称，应该使用"QuizTypeID"或"ID"来解决这个问题，而不是只使用"quizType"。

英文:

You are doing wrong name for "QuizType" class Primary Key instead of just "quizType" you should do "QuizTypeID" or "ID" and this will resolve the issue.

huangapple
  • 本文由 发表于 2023年8月9日 00:22:48
  • 转载请务必保留本文链接：https://go.coder-hub.com/76861477.html
  • c#
  • entity-framework-core
  • visual-studio-2022
匿名

发表评论

匿名网友

:?: :razz: :sad: :evil: :!: :smile: :oops: :grin: :eek: :shock: :???: :cool: :lol: :mad: :twisted: :roll: :wink: :idea: :arrow: :neutral: :cry: :mrgreen:

确定