Question

[Table("Categories")]
public class Category
{
    public Category()
    {       
        Products = new HashSet<Product>();
    }
    public int CategoryId { get; set; }
    public string CategoryName { get; set; }
    public virtual ICollection<Product> Products { get; set; }
}

[Table("Product")]
public class Product
{       
    public int ProductId { get; set; }
    [Required, Display(Name = "Product Name")]
    public string ProductName { get; set; }
    public DateTime Created { get; set; }
    public int CategoryId { get; set; }
    public virtual Category Categories { get; set; }
}

以上是两个表格，我想显示类别列表，包括每个类别中的产品数量。我该如何使用它？

Answer 1

令人惊讶的是，在重复的问题+答案和这里给出的答案中，对于任何你可以做的事情都没有发生：

var counts = from c in context.Categories
             select new
             {
                 c.CategoryName,
                 ProductCount = c.Products.Count()
             };

Answer 2

var categoryCounts =
    from p in products
    group p by p.Category into g
    select new { Category = g.Key, ProductCount = g.Count() };

Count of all products by category

如何显示一对多关系表中的记录？

2 个答案: