Query syntax fromouter-varinouter-enumerablejoininner-varininner-enumerableonouter-key-exprequalsinner-key-expr[ into identifier ] Overview Join 和 GroupJoin 将两个输入序列网格化为一个输出序列。 Join 发出平坦的输出; GroupJoin 发出分层输出。 Join 和 GroupJoin 提供了 Select 和 SelectMany 的替代策略。
QueryVMethodSyntax { static void Main() { int[] numbers = { 5, 10, 8, 3, 6, 12}; //Query syntax: IEnumerable<int> numQuery1 = from num in numbers where num % 2 == 0 orderby num select num; //Method syntax: IEnumerable<...
它创建可以执行的后台代码对象,只有在程序的控制流遇到访问查询变量的语句时才会执行2.2join子句 如果您对SQL中的join比较熟悉的话,那么LINQ中的join对你来说也不是什么难事,不熟悉的话,,当我没说。 我们可以使用join来结合两个或更多集合中的数据,它接受两个集合然后创建一个临时的对象集合?12varquery =fromsins...
<Standard Query Operators> <lambda expression> <result formation> //string collectionIList<string> stringList =newList<string>() {"C# Tutorials","VB.NET Tutorials","Learn C++","MVC Tutorials","Java"};//LINQ Query Syntaxvarresult =fromsinstringListwheres.Contains("Tutorials")selects; 查询语...
A join of two data sources is the association of objects in one data source with objects that share a common attribute in the other data source. For more information, see Standard Query Operators Overview.The examples in this topic demonstrate how to use the GroupJoin and Join methods to ...
All the Join examples on the wiki use linq's query syntax (eg: from u in Users select u.Name), but I'm used to the fluent/method syntax (eg: Users.Select(u => u.Name)). Why can't I do something like the following: db.Users.LeftJoin(db.Po...
然後,它會將 傳遞給MethodCallExpressionCreateQuery<TElement>(Expression)參數之 屬性所Provider表示的方法IQueryProviderouter。 執行表示呼叫Join<TOuter,TInner,TKey,TResult>(IQueryable<TOuter>, IEnumerable<TInner>, Expression<Func<TOuter,TKey>>, Expression<Func<TInner,TKey>>, Expression<Func<TOuter,TInner...
.NET Language-Integrated Query Getting Started with Standard Query Operators Language Features Supporting the LINQ Project More Standard Query Operators Query Syntax LINQ to SQL: SQL Integration LINQ to XML: XML Integration Summary .NET Language-Integrated Query After two decades, the industry has reach...
Actually, it provides two variations, paralleling the syntax variations supported by different SQL vendors. The first syntax uses the Join keyword to specify a field-specific link. The following query "inner joins" the Library and Writers tables at the expected AuthorID connection point. Copy ...
Actually, it provides two variations, paralleling the syntax variations supported by different SQL vendors. The first syntax uses the Join keyword to specify a field-specific link. The following query "inner joins" the Library and Writers tables at the expected AuthorID connection point. 複製 ...