如何从单独的视图发布一对多关系？

Question

我有一个创纪录的课程和一个汽车班。一个记录可以有多辆车。我试图使用RecordID作为两者之间的关键。在第一种观点中，我的表格填补了记录类的模型。然后，我想要采取不同的观点，并将汽车添加到记录中。一旦我导航到第二个视图，我怎么能告诉记录ID使用的汽车？我正在阅读有关ViewModels和Unit of Work等内容。不确定的差异和/或如果这些是我正在寻找。我将包含我的模型和存储库方法中的一些代码。谢谢！

Record.cs

namespace Train.Models { 
public class Record { 
    public int RecordId { get; set; } 
    public int Quantity { get; set; } 
    public DateTime DateCreated { get; set; } 
    public bool IsActive { get; set; } 
    public string UserId { get; set; } 
    public virtual ICollection<Cars> Cars { get; set; } 
} 

}

Cars.cs

namespace Train.Models { 
public class Cars { 
    public int Id { get; set; } 
    public string EmptyOrLoaded { get; set; } 
    public string CarType { get; set; } 
    //Hopper, flatbed, tank, gondola, etc. 
    public string ShippedBy { get; set; } 
    //UP(Union Pacific) or BNSF 
    public string RailcarNumber { get; set; } 
    //public virtual ApplicationUser ApplicationUser { get; set; } 
    public string UserId { get; set; }  
    public virtual Record Record { get; set; } 

} 

}

RecordRepository.cs

public void SaveRecord(Record recordToSave) { 

     if (recordToSave.RecordId == 0) { 
      recordToSave.DateCreated = DateTime.Now; 
      _db.Record.Add(recordToSave); 
      _db.SaveChanges(); 

     } else { 
      var original = this._db.Record.Find(recordToSave.RecordId); 
      original.Quantity = recordToSave.Quantity; 
      original.IsActive = true; 

      _db.SaveChanges(); 
     } 
    } 

CarsRepository.cs

public void SaveCar(Cars carToSave) { 
     if (carToSave.Id == 0) { 
      _db.Cars.Add(carToSave); 
      _db.SaveChanges(); 

     } else { 
      var original = this.Find(carToSave.Id); 
      original.EmptyOrLoaded = carToSave.EmptyOrLoaded; 
      original.CarType = carToSave.CarType; 
      original.ShippedBy = carToSave.ShippedBy; 
      original.RailcarNumber = carToSave.RailcarNumber; 
      _db.SaveChanges(); 
     } 

    } 

Answer 1

你必须设置一个外键，您跑车的记录ID。只需在汽车模型中为RecordID添加另一列即可。

插入记录后，必须返回插入的ID并将此记录ID设置为汽车物件，然后将其保存到数据库。

public void AddCars(int recordID, List<Cars> carsToSave) { 
    foreach(Cars car in carsToSave){ 
     car.RecordID = recordID; 
     _db.Cars.Add(car); 
    } 
    _db.SaveChanges(); 
} 

public void EditCars(List<Cars> carsToEdit){ 
    foreach(Cars car in carsToEdit){ 
     Cars editCar = this.Find(car.Id); 
     editCar.EmptyOrLoaded = car.EmptyOrLoaded; 
     editCar.CarType = car.CarType; 
     editCar.ShippedBy = car.ShippedBy; 
     editCar.RailcarNumber = car.RailcarNumber; 
     editCar.ApplicationUser = car.ApplicationUser; 
     editCar.UserId = car.UserId; 
     _db.SaveChanges(); 
    } 
}