我正在尝试选择一些不在我的分组依据中的属性。这可能吗？
var r = from w in drinks.ToList()
group w by new{
w.DrinkId
} into wGroup
select new DrinksValue(){
DrinkId = wGroup.DrinkId,
CatId = // trying to pull from wGroup???
Lasting = // trying to pull from wGroup???
DrinkTypes = wGroup.Select( x => new DrinkAttributes { Taste = wGroup.Key.Flavor, Benefit = wGroup.Sum(x => x.Value)
}).ToList()
};
如何从drinks.tolist()中获取CatId和持久属性？
如果我将它们添加到组中，就像w.drinkid、w.flavor、w.value、w.catid、w.lenerate，那么我的结果就会混乱。
我可以使用.sum获得其他属性，如value，但这些属性不是计算值。
数据示例：
DrinkId | CatId | Lasting | Flavor | Value
------------------------------------------
1 2 5.1 orange 11.0
1 2 5.1 blue 09.0
1 2 6.0 red 10.0
2 3 6.0 red 10.0
2 3 6.0 yellow 01.0
希望将结果按如下方式分组：
{
"DrinkId": 1,
"CatId": 2,
"Lasting": 5.1,
"DrinkTypes": [{ Taste: orange, Benefit: 11.0}, {Taste: blue, Benefit: 09.0}, {Taste: red, Benefit: 10.0}]
}
此查询应起作用：
var query =
from w in drinks
group w by new { w.DrinkId, w.CatId, w.Lasting } into wGroup
select new DrinksValue
{
DrinkId = wGroup.Key.DrinkId,
CatId = wGroup.Key.CatId,
Lasting = wGroup.Key.Lasting,
DrinkTypes = wGroup.Select(x => new DrinkAttributes
{ Taste = x.Flavor, Benefit = x.Value }
).ToList()
}
};
var r = query.ToList()
通过将这些属性包含在groupby中，您应该能够获得所需的结果，至少您的示例数据显示的DrinkId、CatId和Deneral的值总是相同的。
var r = from w in drinks
group w by new{
w.DrinkId,
w.CatId,
w.Lasting
} into wGroup
select new DrinksValue(){
DrinkId = wGroup.DrinkId,
CatId = wGroup.CatId
Lasting = wGroup.Lasting,
DrinkTypes = wGroup.Select( x => new DrinkAttributes { Taste = wGroup.Key.Flavor, Benefit = wGroup.Sum(x => x.Value)}).ToList()
};
