Question

我在下面遇到错误，并且不明白为什么，因为数据库中确实存在DepartmentID列，这是我的代码

基本上我有两个相关的表（1）具有PK DepartmentID的Departments和（2）具有FK DepartmentID的Departments_Category_Registration

控制器

    public async Task<IActionResult> Index(string Categories)
    {

        ViewData["Dept"] = "No Records Found!";
        Categories = Categories.Replace("_", " ");


        //CHECK FOR INTEGER
        try
        { Int32.Parse(Categories); }
        catch //(Exception err)
        { }

        if (Categories != null)
        {




            if (Categories.Trim() != "")
            {
                Categories = Categories.ToLower().Trim();
                // DATABASE 2 - Main records
                var DataContext2 = _context.Departments_Category_Registration.Include(c => c.Departments)
                   .Where(r => r.Departments.Department_Name == Categories).Select(u => new Departments_Category_Registration
                   {
                       CategoryID = u.CategoryID,
                       Category_Name = u.Category_Name,
                       DepartmentID = u.DepartmentID,
                       Description = u.Description



                   });

                ViewData["Dept"] = Categories;
                return View(await DataContext2.ToListAsync());

            };
        };
        var DataContext = _context.Departments_Category_Registration.Include(c => c.Departments);
       return View(await DataContext.ToListAsync());
    }

//错误消息

 return View(await DataContext2.ToListAsync());

SqlException: Invalid column name 'DepartmentsDepartmentID'.

Answer 1

在[ForeignKey]类中使用Departments_Category_Registration批注，如下所示：

1。在从属类的外键属性上，传入导航属性的名称：

  public class Departments_Category_Registration
{
    [Key]
    public int CategoryID { get; set; } 

    [ForeignKey("Departments ")]
    public int DepartmentID { get; set; } 
    public Departments Departments { get; set; }   
}

2。在依赖类的导航属性上，传入外键属性的名称：

public class Departments_Category_Registration
{
    [Key]
    public int CategoryID { get; set; } 

    public int DepartmentID { get; set; } 
    [ForeignKey("DepartmentID ")]
    public Departments Departments { get; set; }   
}

您可以参考this article about the ForeignKey Attribute。

无效的列名称Departments.DepartmentID

1 个答案: