我有以下模型:
public Class Category{
public int Id {get;set;}
public string Name {get;set;}
public ICollection<SubCategory> SubCategories {get;set;}
}
public Class SubCategory{
public int Id {get;set;}
public string Name {get;set;}
public int CategoryId { get; set; }
public virtual Category Category{ get; set; }
public ICollection<Ticket> Tickets { get; set; }
}
public class Ticket {
public Ticket();
public int Id { get; set; }
public virtual SubCategory SubCategory{ get; set; }
public int SubCategoryId{ get; set; }
}
我想通过以下查询按类别分组获取数据,并获得每个子类别中票的数量:
Entities
.Include(h => h.SubCategories )
.ThenInclude(s => s.Tickets)
.GroupBy(s => s.Id)
.Select(t => new Cata {
Name = t.FirstOrDefault().Name,
Children = GetChildern(t.FirstOrDefault().SubCategories )
});
public List<SubCat> GetChildern(IEnumerable<SubCategories> subs)
{
var output = new List<SubCat>();
foreach (var sub in subs) {
var subcat = new SubCat();
subcat.Name = sub.Name;
if (sub.Tickets != null) {
subcat.Size = sub.Tickets.Count;
}
output.Add(subcat);
}
return output;
}
使用上述查询,所有票的数量始终为零,但实际上存在票。
GroupBy
,并避免使用导致客户端评估的自定义方法。 - Ivan Stoev