【高分在线急等】LINQ查询问题，代码已贴出
-----------------Sqlserver表数据Category--------------------------
表结构：
ID Category
1 分类1
2 分类2
3 分类3
4 分类4
5 分类5
-----------------Sqlserver表数据Detail--------------------------
表结构：
ID CategoryID Name
1 1 子类1
2 1 子类2
3 2 子类3
4 2 子类3
5 2 子类3
--------------需用Linq查出结果----------------------------------
[{"CategoryName":"分类1",
"DetailCount":2,
Items:[{"ItemName":"子类1",Count:1}
{"ItemName":"子类2",Count:1}]
}
{"CategoryName":"分类2",
"DetailCount":3,
Items:[{"ItemName":"子类3",Count:3}]
}
]
-------------已建立的实体类-------------------------------------
class Category
//大类名称
public string CategoryName;
//下面子类总数
public int DetailCount;
//子类list
public List<Detail> item;
class Detail
//子类名称
public string ItemName;
//子类个数
public int Count;
LINQ 类
[解决办法]
var query = from c in Category
join d into Detail
on c.id equals d.CategoryID into g
select new { CategoryName = c.Category, DetailCount = g.Count(), Items = g };
[解决办法]
class Program
{
static void Main(string[] args)
{
List<Category> categorys = new List<Category>
{
new Category {Id=1,Name="分类1"},
new Category {Id=2,Name="分类2"},
new Category {Id=3,Name="分类3"},
new Category {Id=4,Name="分类4"},
new Category {Id=5,Name="分类5"},
};
List<Detail> details = new List<Detail>
{
new Detail{Id=1,CategoryId=1,Name="子类1-1"},
new Detail{Id=2,CategoryId=1,Name="子类1-2"},
new Detail{Id=3,CategoryId=2,Name="子类2-1"},
new Detail{Id=4,CategoryId=2,Name="子类2-2"},
new Detail{Id=5,CategoryId=3,Name="子类3-1"},
new Detail{Id=6,CategoryId=3,Name="子类3-2"},
new Detail{Id=7,CategoryId=3,Name="子类3-3"},
};
var query = details.GroupBy(g => new { g.CategoryId }).Select(s => new Result
{
CategoryName = categorys.FirstOrDefault(f => f.Id == s.Key.CategoryId).Name,
DetailCount = details.Where(w => w.CategoryId == s.Key.CategoryId).Count(),
Items = details.Where(w => w.CategoryId == s.Key.CategoryId).ToList()
});
}
}
public class Result
{
public string CategoryName { get; set; }
public Int32 DetailCount { get; set; }
public List<Detail> Items { get; set; }
}
public class Category
{
public Int32 Id { get; set; }
public string Name { get; set; }
}
public class Detail
{
public Int32 Id { get; set; }
public Int32 CategoryId { get; set; }
public string Name { get; set; }
}
