Question

我要做的是从我的数据库中获取特定值并将其解析为视图以在表中显示它。我遇到了与The model item passed into the dictionary is of type .... {Models.App} but what I passed is {Models.App, System.Double}相同的问题，并试图以类似的方式解决我的问题。所以基本上我在模型中创建了一个类：

 public Vehicle manur_name {get; set;}
 public Vehicle manur_date { get; set; }
 public Vehicle daily_hire_rate { get; set; }

但是当我在linq查询中使用它时，它给了我和错误。

 var s = from veh in db.Vehicles
 join c in db.VehicleCategories on veh.vehicle_category_code equals  c.
 join m in db.Models on veh.model_code equals m.model_code
 join man in db.Manufacturers on veh.manufacturer_code equals man.manufacturer_code
 where c.vehicle_category_description == cat && m.body_style == b                         
            select new CarClass {
                          manur_name = man.manufacturer_name, 
                          manur_date = m.model_code, 
                          daily_hire_rate = veh.daily_hire_rate};

它给了我错误：

错误：无法将类型'decimal'隐式转换为 'carRentalMVC.Models.Vehicle'无法隐式转换类型'string' to'carRentalMVC.Models.Vehicle'无法隐式转换类型 'string'到'carRentalMVC.Models.Vehicle'

以下是解决问题后控制器中的内容：

        CarRentalDatabaseDataContext db = new CarRentalDatabaseDataContext();
    public ActionResult Index(String cat, String b, String sort)
    {
        String day_hire = "Daily hire rate";
        String man_date = "Manufacturing date";
        string man_n = "Manufacturer's name";

        var s = db.Vehicles.Where(c => c.Model.body_style == b)
             .Select(u => new CarClassViewModel { 
                 manur_name = u.Manufacturer.manufacturer_name, 
                 model_code = u.model_code,
                 daily_hire_rate = u.daily_hire_rate,
                 manur_date = u.manufacturing_date
             })
             .Distinct(); //I don't need repeating data

        //this is for sorting them, but I haven't implemented this in the view yet. 
        if (sort == man_n){s = s.OrderBy(c=>c.manur_name);}
        else if (sort == man_date){s = s.OrderBy(c =>c.manur_date);}
        else if (sort == day_hire){s = s.OrderBy(c => c.daily_hire_rate);}
        else{s = s.OrderBy(c => c.daily_hire_rate);}

        var v = s.Select(u => new CarClassViewModel
        {
            manur_name = u.manur_date,
            model_code = u.model_code,
            daily_hire_rate = u.daily_hire_rate,
        }); //this is for returning values I need

        return View(v); //I've tried View(v.ToList()) as well
    }

现在返回表格中的空行。我不解析方法的数据是否重要？

Answer 1

我不确定我做错了什么。

您的数据模型非常混乱。即使不遵守命名惯例，也请查看您的属性：

public Vehicle manur_name {get; set;}
public Vehicle manur_date { get; set; }
public Vehicle daily_hire_rate { get; set; }

汽车的制造商名称不是车辆 - 它可能是一个字符串。汽车的制造日期不是车辆 - 它可能是DateTime。汽车的每日租车率不是车辆 - 它可能是decimal。所以你的模型应该是这样的：

public string ManufacturerName { get; set; }
public DateTime ManufacturingDate { get; set; }
public decimal DailyHireRate { get; set; }

让您的数据模型正确，其他所有内容应该变得更简单批次。话虽如此，这看起来也很可疑：

manur_date = m.model_code

“日期”和“代码”对我来说听起来不一样。

在linq查询中将类型赋予匿名类型

1 个答案: