C# Entity Framework 代码首次迁移错误，虽然实际定义了键但未定义键

Question

我正在使用 Entity Framework 代码优先方法。在 运行ning enable-migrations 和 add-migration:

之后，我在空白数据库中 运行 Update-Database -script 时出现以下错误

standardvba.DataAccessLayer.LessonQuestion: : EntityType 'LessonQuestion' has no key defined. Define the key for this EntityType.
LessonQuestions: EntityType: EntitySet 'LessonQuestions' is based on type 'LessonQuestion' that has no keys defined.

LessonQuestion.cs:

public partial class LessonQuestion
{
    public LessonQuestion()
    {
        this.LessonQuestionDetails = new List<LessonQuestionDetail>();
    } 

    [Key]
    public int QuestionID; // Key is defined

    public int OrderNumber;

    [ForeignKey("ParentQuestion")]
    public int ParentQuestionID;  

    [ForeignKey("Lesson")]
    public int LessonID { get; set; }

    [ForeignKey("ActionedBy")]    
    public int ActionedByUserID { get; set; }
    [MaxLength(1000)]
    public string Question { get; set; } 
    public bool IsApproved { get; set; }

    [Required]  // Sets the CASCADE constraint, while creating table
    public virtual CourseLesson Lesson { get; set; }

    public virtual SiteUser ActionedBy { get; set; }

    public virtual ICollection<LessonQuestionDetail> LessonQuestionDetails { get; set; }

    public virtual LessonQuestion ParentQuestion { get; set; }
}

我尝试了删除和重新创建 Migrations 文件夹等选项，但没有用。

Answer 1

密钥必须是 Public Property。在您的情况下，它是一个字段。你需要改变它如下

[Key]
public int QuestionID{get;set;}