Question

我想要一个lambda表达式，当我从ID为1030的数据库中调用 Company 来带给我公司信息时，该列表包含该公司拥有的所有 car 与每辆汽车相关的所有图像的列表（每辆汽车有4张图像）。

我的课程结构：

public partial class Companies
    {
        public int CompanyId { get; set; }
        public string Name { get; set; }
        public string Description { get; set; }
        public string Tel { get; set; }
        public string Logo { get; set; }
        public int? Owner { get; set; }
        public int? Address { get; set; }
        public int? Publish { get; set; }

        public ICollection<Cars> Cars { get; set; }
}
public partial class Cars
    {

        public int CarId { get; set; }
        public string Manufacturer { get; set; }
        public string Model { get; set; }
        public string Year { get; set; }
        public string Description { get; set; }
        public decimal? Price { get; set; }
        public int? CarCatId { get; set; }
        public int? CompanyId { get; set; }
        public int? CharacteristicId { get; set; }

        public ICollection<CarImages> CarImages { get; set; }
}

public partial class CarImages
    {
        public int CarImagesId { get; set; }
        public string Image { get; set; }
        public int? CarId { get; set; }

        public Cars Car { get; set; }
    }

您可以在 Company 类中看到，我引用了 Cars 类作为ICollection，并且在 Cars 类中使用了相同的内容 CarImages 。

我已经尝试了很多东西，包括：

var compInfo = _context.Companies.SelectMany(cr => cr.Cars.SelectMany(i =>i.CarImages.Where(car => car.CarId == car.Car.CarId))).ToList();

var compInfo2 = _context.Companies.Include(a => a.AddressNavigation).Include(cr =>cr.Cars.).FirstOrDefault(c => c.CompanyId == id);

第二个带给我公司的信息（地址）和汽车列表（成功了一半），但没有图像。

第一个只是给我列出了图像表的所有信息。

Answer 1

我找到了解决方案。

//Get the Company with id == 1030.
    var x = _context.Companies.Include(a => a.AddressNavigation).Include(c => c.Cars).Where(c => c.CompanyId == id).FirstOrDefault();

//Get the Car ICollection and include the CarImages ICollection depending on CompanyID. 
    var y = _context.Cars.Include(img => img.CarImages).Where(cr => cr.CompanyId == x.CompanyId).ToList();

//Now each Car in our Cars list has a list of CarImages related to each car. Finaly pass our data to our Company var(x) and send it to View.
    x.Cars = y;
    return View(x);

使用Lambda表达式在ICollection中调用ICollection

1 个答案: