在MVC中生成Model时出错

Question

在ASP.Net中生成模型时出现以下错误：

  

MvcApplication1.Models.Department :: EntityType＆＃39; Department＆＃39;没有定义键。定义EntityType的密钥。    department：EntityType：EntitySet＆＃39; department＆＃39;是基于类型＆＃39;部门＆＃39;没有键定义。

这是一个包含更多细节的屏幕截图：

我将主键添加到Department表中：

{    
    [Table("department")]
    public class Department
    {
        public int dept id { get; set; }
        public string department { get; set; }
        public List<Employee> Employees { get; set; }
    }
}

Answer 1

您需要在deptid字段中添加[key] annotation：

{    
    [Table("department")]
    public class Department
    {
        [Key]
        public int deptid { get; set; }
        public string department { get; set; }
        public List<Employee> Employees { get; set; }
    }
}

Answer 2

 department table. ' {

[Table("department")]
public class Department
{
   [Key]
    public int dept id { get; set; }
    public string department { get; set; }
    public List<Employee> Employees { get; set; }
}
}`

添加关键字属性，请参阅msdn

Answer 3

另一种选择是将let students = [['David', 80], ['Vinoth', 77], ['Goren', 55]]; // Define rating function: let rate = (grade) => grade <= 60 ? 'F' : grade <= 70 ? 'D' : grade <= 80 ? 'C' : grade <= 90 ? 'B' : 'A'; // Map students to phrases: let phrases = students.map((student) => `${student[0]}'s grade is ${student[1]} and is ${rate(student[1])} grade.`); // Output DOM nodes: phrases.forEach((phrase) => { let el = document.createElement('div'); el.textContent = phrase; document.body.appendChild(el); });更改为public int deptid或public int Id。这是一个内置的EF约定，如果您使用此语法，则不需要public int DepartmentId属性。

https://msdn.microsoft.com/en-us/library/jj679962(v=vs.113).aspx#Anchor_1