Foreignkey Name error in Entity Framework Code First

Question

When I'm using the following code, the tables are generated successfully with the Primary key and Foreign Key relations.

 [Table("tblDepartments")]
    public class DepartmentModel
    {
        [Key]
        public int DepartmentID { get; set; }
        public string Name { get; set; }
        public string Location { get; set; }
        public ICollection<EmployeeModel> Employees { get; set; }
    }



    [Table("tblEmployees")]
    public class EmployeeModel
    {
        [Key]
        public int EmployeeID { get; set; }
        public string Name { get; set; }
        public string Gender { get; set; }
        public string City { get; set; }      
        public virtual DepartmentModel DID { get; set; }

    }

But when I use the following Code, I'm Getting error:

[Table("tblDepartments")]
    public class DepartmentModel
    {
        [Key]
        public int DepartmentID { get; set; }
        public string Name { get; set; }
        public string Location { get; set; }
        public ICollection<EmployeeModel> Employees { get; set; }
    }



    [Table("tblEmployees")]
    public class EmployeeModel
    {
        [Key]
        public int EmployeeID { get; set; }
        public string Name { get; set; }
        public string Gender { get; set; }
        public string City { get; set; }     

        [ForeignKey("DeptID")]
        public virtual DepartmentModel DID { get; set; }

    }

ERROR:

The ForeignKeyAttribute on property 'DID' on type 'MvcApplication1.Models.EmployeeModel' is not valid. The foreign key name 'DeptID' was not found on the dependent type 'MvcApplication1.Models.EmployeeModel'. The Name value should be a comma separated list of foreign key property names.

Please Help. Thanks in advance.

Answer 1

The problem is with your EmployeeModel as you are missing departmentid field in your table as suggested by Gert. you can use the below for EmployeeModel

[Table("tblEmployees")]
public class EmployeeModel
{
    [Key]
    public int EmployeeID { get; set; }
    public string Name { get; set; }
    public string Gender { get; set; }
    public string City { get; set; }     
    public int DeptID { get; set; } //<-- You forgot to add this
    [ForeignKey("DeptID")]
    public virtual DepartmentModel DID { get; set; }

}

Answer 2

Put the foreign key as a property inside your model then have the navigation property point to it.

public class EmployeeModel
    {
        [Key]
        public int ID { get; set; }
        public int DeptID { get; set; }
        public string Name { get; set; }
        public string Gender { get; set; }
        public string City { get; set; }     

        [ForeignKey("DeptID")]
        public virtual DepartmentModel DID { get; set; }

    }