3.标准查询操作符(Standard Query Operators):LINQ 提供了一组标准的查询操作符(例如 `Where`、`Select`、`OrderBy` 等),这些操作符是对 LINQ 查询的构建块,使得可以构建灵活的查询表达式。 查询执行过程: 1.查询构建阶段:在编写 LINQ 查询时,查询不会立即执行,而是被解释为表达式树。 2.表达式树解析阶段:查询...
代码语言:csharp 复制 var sortedData = data.OrderBy(x => x.Name).ThenBy(x => x.Age); 代码语言:txt 复制 上述代码将数据先按照Name字段进行升序排序,然后再按照Age字段进行升序排序。 Select top 1操作简化: 在Linq中,使用Select操作可以选择指定的字段,使用Take操作可以选择指定数量的记录。为了...
db.S.Where(q=>q.TypeID==1).OrderByDesending(q=>q.ID).Take(1);
1privatestaticvoidSortDescendingWithMethod()2{3vardescSort =Formulal.GetChampions()4.Where(r => r.Country =="中国")5.OrderByDescending(r =>r.Wins)6.Select(r =>r);7foreach(vari
linq002 1 - C#进阶-LINQ表达式基础语法Ⅰ ① Select 查询 代码语言:javascript 复制 /* SQL里的表达: 查找用户里职业是医生的人的姓名,按照年龄倒序输出 */select name from user where occupation="Doctor"order by age desc; 代码语言:javascript
The type of the key returned bykeySelector. Parameters source IEnumerable<TSource> A sequence of values to order. keySelector Func<TSource,TKey> A function to extract a key from an element. Returns IOrderedEnumerable<TSource> AnIOrderedEnumerable<TElement>whose elements are sorted in descendin...
conststringsql="SELECT TOP 1 Id, FirstName FROM Person ORDER BY Id DESC";IEnumerable<dynamic>result=personRepository.QueryDynamic(sql); License Copyright 2011 Thad Smith, Page Brooks, Ryan Watson and contributors Licensed under the Apache License, Version 2.0 (the "License"); you may not use ...
Linq to SQL - Select top 1... Linq to Sql Join w/ Not Equals? Linq to SQL meltdown: Invalid attempt to call Read when reader is closed. LINQ to SQL: SELECT First letter of name, order by, and return DISTINCT - getting duplicates Linq using Sum() with NO GROUP BY LINQ with lambd...
前面的所有示例都将转换为查询 URI:https://localhost:12345/northwind.svc/Customers()?$orderby=CompanyName,PostalCode desc。投影下面的示例显示了将返回的数据投影到较窄的 CustomerAddress 类型的等效查询:使用LINQ 查询语法: VB 复制 Dim projectedQuery = From c In context.Customers Select New Customer...
VisitOrderBy(mc.Arguments[0], orderDescLambda, OrderDirection.Descending);break;case"Select":// is this really a proper Select?varselectLambda = GetLambdaWithParamCheck(mc);if(selectLambda ==null)break; VisitSelect(mc.Arguments[0], selectLambda);break;case"Take":if(mc.Arguments.Count !=2)...