Question

有两张桌子。一个用于Fruit，另一个用于FruitBag。可能有许多FruitBag包含许多Fruit。我希望能够计算出特定水果袋内相同水果的数量。

public ActionResult FruitCheck(int fruitBagId, int fruitId)
{
    var getFruitBag = db.FruitBags.SingleOrDefault(fb => fb.Id == fruitBagId);

    int Amount = getFruitBag.// check amount same fruit-id inside current FruitBag
    ....
}

以下代码不起作用，但它是关于我的想法，所以你明白我的意思：

int Amount = getFruitBag.Count(c=> c.Fruit.Where(f=> f.Id == fruitId))

  public partial class FruitBag {
        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2214:DoNotCallOverridableMethodsInConstructors")]
        public FruitBag() {
            this.Fruits = new HashSet<Fruit>();
        }
        public System.Guid Id { get; set; }

        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
        public virtual ICollection<Fruit> Fruits { get; set; }
    }

public partial class Fruit {
    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2214:DoNotCallOverridableMethodsInConstructors")]
    public Fruit() {
        this.FruitBags = new HashSet<FruitBag>();
    }

    public System.Guid ID { get; set; }
    public string Type { get; set; }
    public int Price { get; set; }

    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
    public virtual ICollection<FruitBag> FruitBags { get; set; }
}

Answer 1

试试这个：

var amount = getFruitBag.Fruit.
      GroupBy(x => x.Id).
      Select(x => new { x.Key, Value = x.Count() }).ToList();

您将获得一个匿名类型，其中包含所有水果及其数量。

数量：从特定的水果袋计算相同数量的水果（清单）

1 个答案: