SQL Server查询到C＃LINQ

Question

我目前有一个艰难的时间将我的SQL查询转换为LINQ，用于正在使用WPF的学校项目，

这是我的SQL查询（完全按照我的期望工作）

select IngrediantName,sum(IngrediantQuantity) as Quantity, IngrediantMeasurementUnit from Users
join Shopping_List
on Users.UserID = Shopping_List.ShoppingListID
join List_Item
on List_Item.ShoppingListID = Shopping_List.ShoppingListID
join Ingrediant
on Ingrediant.IngrediantID = List_Item.IngrediantID
where Users.UserID = 1
group by IngrediantName,IngrediantMeasurementUnit

我到目前为止的查询

var query = from user in dbContext.Users
                        join shoppingList in dbContext.ShoppingLists on user.UserId equals shoppingList.UserId
                        join listItem in dbContext.ListItems on shoppingList.ShoppingListId equals listItem.ShoppingListId
                        join ingrediant in dbContext.Ingrediants on listItem.IngrediantId equals ingrediant.IngrediantId
                        where currentUserNumber == user.UserId
                        
                        select new
                        {
                            name = ingrediant.IngrediantName,
                            quantity = ingrediant.IngrediantQuantity,
                            unit = ingrediant.IngrediantMeasurementUnit,
                        };

，这是 。到目前为止，我尝试了

            var query = from user in dbContext.Users
                        join shoppingList in dbContext.ShoppingLists on user.UserId equals shoppingList.UserId
                        join listItem in dbContext.ListItems on shoppingList.ShoppingListId equals listItem.ShoppingListId
                        join ingrediant in dbContext.Ingrediants on listItem.IngrediantId equals ingrediant.IngrediantId
                        where currentUserNumber == user.UserId
                        group ingrediant by ingrediant.IngrediantQuantity into x
                        
                        select new
                        {
                            name = x.GroupBy(x => x.IngrediantName),
                            quantity = x.Sum(x => x.IngrediantQuantity),
                            unit = x.GroupBy(x => x.IngrediantMeasurementUnit),
                        };

这个错误

参数类型'system.linq.iqueryable 1 [system.linq.igrouping 2 [System.String，Microsoft.EntityFrameWorkcore.Query.Query.Query.TransparentIdentifierFactory+thransparentifierfactory+thransparentifentifier+code> Code> 2 [Microsoft.entityframeworkcore.query.query.query.query.query.query.query.query.query.query.query.query.query.query.query .TransparentIdentifierFactory+TransparentIdentifier2

如果有人可以将我指向正确的方向，我会很感激，如果您需要更多信息，我会确保提供

它

Answer 1

更新

我在这里可以找到其他人问题的答案

var query = 
    from user in dbContext.Users
    join shoppingList in dbContext.ShoppingLists 
        on user.UserId equals shoppingList.UserId
    join listItem in dbContext.ListItems 
        on shoppingList.ShoppingListId equals listItem.ShoppingListId
    join ingrediant in dbContext.Ingrediants 
        on listItem.IngrediantId equals ingrediant.IngrediantId
    where currentUserNumber == user.UserId
    group ingrediant by new { name = ingrediant.IngrediantName, unit = ingrediant.IngrediantMeasurementUnit } into x
    select new
    {
        name = x.Key.name,
        quantity = x.Sum(x => x.IngrediantQuantity),
        unit = x.Key.unit,
    };

如果您查看组行，
将 ingrediant by new { name = ingrediant.IngrediantName, unit = ingrediant.IngrediantMeasurementUnit } 分组到 x

根据我的理解，您使用 new 创建一个新的选择器，然后您可以使用 x.key.name 和 x。 key.unit 其中名称和单位只是一些变量