LINQ Method Syntax //string collectionIList<string> stringList =newList<string>() {"C# Tutorials","VB.NET Tutorials","Learn C++","MVC Tutorials","Java"};//LINQ Query Syntaxvarresult = stringList.Where(s => s.Contains("Tutorials")); //Student collectionIList<Student> studentList =newList...
Query Syntax Versus Fluent Syntax Query 和 fluent syntax 各有优势,但是它们的本质是一样的,看实际情况来使用它们. Mixed - Syntax Queries 如果查询操作符不支持查询语法,则可以混合使用查询语法和连贯语法。 怎么方便怎么来,例如: string[] names = {"Tom","Dick","Harry","Mary","Jay"};intmatches = ...
int[] numbers = [5,10,8,3,6,12];//Query syntax:IEnumerable<int> numQuery1 =fromnuminnumberswherenum %2==0orderbynumselectnum;//Method syntax:IEnumerable<int> numQuery2 = numbers .Where(num => num %2==0) .OrderBy(n => n);foreach(intiinnumQuery1) { Console.Write(i +" ")...
var query = from item in dataSource [join clause] [where clause] [group by clause] [orderby clause] select item;from：指定数据源和范围变量，用于指定要查询的集合或数据源以及每个元素的范围变量。join：用于指定多个数据源之间的关联操作。where：用于指定筛选条件，过滤满足特定条件的...
For more information, see Query Syntax and Method Syntax in LINQ. Classification of standard query operators by manner of execution The LINQ to Objects implementations of the standard query operator methods execute in one of two main ways: immediate or deferred. The query operators that use ...
class Pet { public string Name { get; set; } public int Age { get; set; } } // Uses method-based query syntax. public static void GroupByEx1() { // Create a list of pets. List<Pet> pets = new List<Pet>{ new Pet { Name="Barley", Age=8 }, new Pet { Name="Boots", Age...
There are two different types of syntax that you can use to query with LINQ: query syntax and method syntax. In the code samples both types are used, as one becomes familiar with with writing queries one style lends itself better than the other. Group by one property and multiple ...
class Pet { public string Name { get; set; } public int Age { get; set; } } // Uses method-based query syntax. public static void GroupByEx1() { // Create a list of pets. List<Pet> pets = new List<Pet>{ new Pet { Name="Barley", Age=8 }, new Pet { Name="Boots", Age...
Query syntax group element-expression by key-expression Overview GroupBy 将平面输入序列组织成组序列。例如,以下按扩展名组织 Path.GetTempPath() 中的所有文件: string[] files = Directory.GetFiles (Path.GetTempPath()); IEnumerable<IGrouping<string,string>> query = files.GroupBy (file => Path.GetEx...
This query has a somewhat strange syntax, but it successfully creates a results set with two columns: FullName (for the author name) and Published (for the collection of books published by a specific author). For each returned record, the Published member is a subordinate collection that can...