c# - 实体类型 ‘Business_attrib2object’ 具有使用数据注释定义的复合主键。要设置复合主键，请使用 Fluent API

Question

我使用流畅的 API 设置复合主键，当我尝试创建 ClassesController(使用 Entity Framework 的 View 的 MVC Controller )时，它仍然是一个错误。

声明类类:

public partial class Classes
{
    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2214:DoNotCallOverridableMethodsInConstructors")]
    public Classes()
    {
        this.Business_attrib2object = new HashSet<Business_attrib2object>();
        this.Objects = new HashSet<Objects>();
    }
    [Key]
    public System.Guid IdClass { get; set; }
    public string Name { get; set; }

    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
    public virtual ICollection<Business_attrib2object> Business_attrib2object { get; set; }
    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
    public virtual ICollection<Objects> Objects { get; set; }
}

声明 Business_attrib2object 类:

 public partial class Business_attrib2object
{
    [Key]
    public System.Guid IdClass { get; set; }
    [Key]
    public System.Guid IdAttribute { get; set; }

    public Nullable<System.Guid> IdAuthor { get; set; }

    public virtual Attributes Attributes { get; set; }
    public virtual Classes Classes { get; set; }
}

数据库上下文:

public class Business_attrib2objectContext : DbContext
{
    public DbSet<Business_attrib2object> Business_attrib2object { get; set; }

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        modelBuilder.Entity<Business_attrib2object>().HasKey(ba => new { ba.IdClass, ba.IdAttribute });      
    }

    public Business_attrib2objectContext(DbContextOptions<Business_attrib2objectContext> options)
        : base(options)
    {
        Database.EnsureCreated();
    }
}

创建 Controller : Creating controller错误: Error message

Answer 1

如果你用过这个:

protected override void OnModelCreating(ModelBuilder modelBuilder)
{
    modelBuilder.Entity<Business_attrib2object>().HasKey(ba => new { ba.IdClass, ba.IdAttribute });      
}

你不需要这个:

public partial class Business_attrib2object
{
    [Key]
    public System.Guid IdClass { get; set; }
    [Key]
    public System.Guid IdAttribute { get; set; }

    ...

只需删除它应该起作用的[Key] 属性即可:

public partial class Business_attrib2object
{
    public System.Guid IdClass { get; set; }
    public System.Guid IdAttribute { get; set; }

    public Nullable<System.Guid> IdAuthor { get; set; }

    public virtual Attributes Attributes { get; set; }
    public virtual Classes Classes { get; set; }
}