Age = 24, City = "Los Angeles", Score = 88 }, new Student { Name = "Eva", Age = 25, City = "San Francisco", Score = 91 }, new Student { Name = "Frank", Age = 23, City = "San Francisco", Score = 87 } }; // 使用LINQ
首先根据学生年级创建每个组,然后根据每个人的姓名进一步细分为小组。 publicvoidQueryNestedGroups() {varqueryNestedGroups =fromstudentinstudents group student by student.Year into newGroup1fromnewGroup2in(fromstudentinnewGroup1 group student by student.LastName) group newGroup2 by newGroup1.Key;//Three...
group student by student.LastName) group newGroup2 by newGroup1.Key;//Three nested foreach loops are required to iterate//over all elements of a grouped group. Hover the mouse//cursor over the iteration variables to see their actual type.foreach(varouterGroupinqueryNestedGroups) { Console.W...
private static voidGroupingWithNestedObjects() {varcountries =fromrinFormula1.GetChampions()grouprbyr.Countryintogorderbyg.Count()descending, g.Keywhereg.Count() >= 2select new{ Country = g.Key, Count = g.Count(), //在此之前与前面是一样的,下面是以每个分组结果的g为基础进行排序和查询,好...
Explicit typing is used // to make clear that, when executed, multiColQuery produces // nested sequences. However, you get the same results by // using 'var'. // The multiColQuery query performs the following steps: // 1) use Split to break each row (a string) into an ...
private static void GroupingWithNestedObjects() { var countries = from r in Formula1.GetChampions() group r by r.Country into g orderby g.Count() descending, g.Key where g.Count() >= 2 select new { Country = g.Key, Count = g.Count(), ...
我不能使用nested_update/ nested _lookup,因为键的结构导致了错误的更新,因为有多个相同的键,但嵌套不同。例如,如果有多个键Z具有不同的“预键”,它们将被nested_update全部更改,这是我不想要的。所以基本上我想以编程的方式做的是: extracted_event. 浏览15提问于2021-07-22得票数 1 回答已采纳...
Microsoft Group By Clause documentation for a base on grouping Suggested reading Microsoft Query clauses documentation Microsoft Create a nested group for basics on nested grouping Microsoft GroupJoin documentation Query vs. Method Syntax in LINQ There are two different types of syntax that you...
string>>> query = list.ChunkBy(p => p.Key);publicstaticvoidGroupByContiguousKeys1(){// ChunkBy returns IGrouping objects, therefore a nested// foreach loop is required to access the elements in each "chunk".foreach(variteminquery) { Console.WriteLine($"Group key ={item.Key}");...
In the lambda expression passed to SelectMany, the nested query applies to a different source, but has in scope the n parameter passed in from the outer source. Thus people.Where is called once for each n, with the resulting sequences flattened by SelectMany for the final output. The result...