LINQ(Language Integrated Query,语言集成查询)是.NET框架中的一项功能,它允许开发者以声明性方式编写查询,并且这些查询可以直接在C#或Visual Basic等语言中执行。LINQ to Objects是LINQ的一个部分,它允许对内存中的对象集合进行查询。 基础概念 Where子句是LINQ中的一个关键组成部分,用于过滤集合中
相当于sql里的in用法:select * from 表 where user_type in (1,5)list= list.Where(a =>"1,5".Contains(a.user_type)).ToList();//此处等同于上面list= list.Where(a => a.user_type =="1"|| a.user_type =="5").ToList();//另一种形式,from开头IList<Model> query = (fromitem...
List<int> numbers = [5,4,1,3,9,8,6,7,2,0];// The query variables can also be implicitly typed by using var// Query #1.IEnumerable<int> filteringQuery =fromnuminnumberswherenumis<3or>7selectnum;// Query #2.IEnumerable<int> orderingQuery =fromnuminnumberswherenumis<3or>7orderbynum...
代码语言:dotnet AI代码解释 /* 遍历 输出 */foreach(UserSalaryuserinUserSalaryList){Console.WriteLine(PrintUserSalaryObject(user));}/* 输出结果 */{id=1,name=ZhangLong,age=38,gender=True,occupation=Teacher,active=True,salary=7800}{id=2,name=ZhangJin,age=18,gender=False,occupation=Student,activ...
varqueryMatchingFiles =fromfileinfileListwherefile.Extension ==".txt"letfileText = File.ReadAllText(file.FullName)wherefileText.Contains(searchTerm)selectfile.FullName;// Execute the query.Console.WriteLine($"""The term "{searchTerm}" was found in:""");foreach(stringfilenameinqu...
var queryResult = from pindb.Products where !(newint?[] { 1, 2 }).Contains(p.CategoryID) select p; 3.LINQ的NOT IN 遍历集合 List<string> source = new List<string>{ "aaa", "bbb" }; List<string> px = new List<string> { "aaa", "bbb", "ccc" }; ...
List<int> numQuery2 = (fromnuminnumberswhere(num %2)==0selectnum).ToList();// or like this:// numQuery3 is still an int[]varnumQuery3 = (fromnuminnumberswhere(num %2)==0selectnum).ToArray(); 此外,还可以通过在紧跟查询表达式之后的位置放置一个foreach循环来强制执行查询。 但是,通过...
an explicit type for non-generic collections Dim query = From student As Student In arrList Where student.Scores(0) > 95 Select student For Each student As Student In query Console.WriteLine(student.LastName & ": " & student.Scores(0)) Next ' Keep the console window o...
int[] validIds = {1, 4, 5 }; var query = from order in db.Orders where validIds.Contains(order.Id) select order 应用方案: public List<GameOrder> GetGameOrderList(GameOrderPageReq dto, out int totalCount, out decimal totalBetAmount, out decimal totalAvailBetAmount, out decimal totalWin...
var Query = from P in persons1 where .Contains("张") || .Contains("李") || .Contains("王") select new PersonModel { Name = , Sex = P.Sex, Age = P.Age, Money = P.Money }; var list = new List<PersonModel>(); list = Query.ToList(); ...