Question

我有一个记录课和一个汽车课。一条记录可以有多辆车。我试图使用RecordID作为两者之间的关键。在第一个视图中，我的表单正在填充记录类的模型。然后我想转到不同的视图并将汽车添加到记录中。一旦我导航到第二个视图，我怎么能告诉汽车使用哪个记录ID？我正在阅读像ViewModels和Unit of Work这样的东西。不确定差异和/或这些是我正在寻找的。我将从我的模型和存储库方法中包含一些代码。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

您必须为记录ID的车型设置外键。只需在RecordID的汽车模型中添加另一列。

插入记录后，您必须返回插入的ID并将此记录ID设置为car对象，然后再将其保存到数据库中。

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();
     }
}

如何从不同的视图发布一对多关系？

1 个答案: