DbSet不能识别它的实体

本文关键字：实体 识别 不能 DbSet | 更新日期: 2023-09-27 18:16:56

我在DbContext类中遇到了DbSet的问题。当我构建解决方案时，它给了我以下错误:

类型或命名空间名称'Student'找不到(您是否缺少using指令或程序集引用?)

下面是我的DbContext类: 
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.ComponentModel.DataAnnotations;
using System.Data.Entity;
namespace CodeFirstMigration.Models
{
    public class StudentDbContext : DbContext
    {
        public StudentDbContext()
            : base("StudentDbContext")
        {
            Database.SetInitializer(new DropCreateDatabaseIfModelChanges<StudentDbContext>());
        }
        public DbSet<Student> Students { get; set; }
        public DbSet<Department> Departments { get; set; }
    }
}

学生类:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.ComponentModel.DataAnnotations;
using System.Linq;
using System.Text;
namespace CodeFirst.Models
{
    public class Student
    {
        public Student()
        {
        }
        [Key]
        public int Id { get; set; }
        public string Name { get; set; }
        [DataType(DataType.Date),
        DisplayFormat(DataFormatString = "{0:dd/MM/yy}", ApplyFormatInEditMode = true)]
        public DateTime? DateOfBirth { get; set; }
        public string EmailId { get; set; }
        public string Address { get; set; }
        public string City { get; set; }
        public Department Department { get; set; } // Navigation Property
    }
}

系类:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.ComponentModel.DataAnnotations;
namespace CodeFirst.Models
{
    public class Department
    {
        public Department()
        {
        }
        [Key]
        public int Id { get; set; }
        public string DepartmentName { get; set; }
        public List<Student> Students { get; set; } // Navigation property
    }
}

Student和Department类以及StudentDbContext都在同一个文件夹中。我尝试包括使用ProjectName.Models.Student和ProjectName.Models.Department，但无效。请帮助!

DbSet不能识别它的实体

您的上下文位于另一个命名空间:

namespace CodeFirstMigration.Models

您是否尝试过添加使用CodeFirst。像这样在你的环境中建模?

using System.ComponentModel.DataAnnotations;
using System.Data.Entity;
using CodeFirst.Models;
namespace CodeFirstMigration.Models
{
    public class StudentDbContext : DbContext
    {
        public StudentDbContext()
            : base("StudentDbContext")
        {
            Database.SetInitializer(new DropCreateDatabaseIfModelChanges<StudentDbContext>());
        }
        public DbSet<Student> Students { get; set; }
        public DbSet<Department> Departments { get; set; }
    }
}
相关文章：