Put field 2 first, then // reverse and combine fields 0 and 1 from the old field IEnumerable<string> query = from line in lines let fields = line.Split(',') orderby fields[2] select $"{fields[2]}, {fields[1]} {fields[0]}"; File.WriteAllLines("spreadsheet2.csv", query.ToArray...
string[] lines = File.ReadAllLines("spreadsheet1.csv");// Create the query. Put field 2 first, then// reverse and combine fields 0 and 1 from the old fieldIEnumerable<string> query =fromlineinlinesletfields = line.Split(',')orderbyfields[2]select$"{fields[2]},{fields[1...
string[] lines = File.ReadAllLines("spreadsheet1.csv");// Create the query. Put field 2 first, then// reverse and combine fields 0 and 1 from the old fieldIEnumerable<string> query =fromlineinlinesletfields = line.Split(',')orderbyfields[2]select$"{fields[2]},{fields[1]...
LINQ queries return enumerable collections of strongly typed objects. A query can return a collection of anonymous types or named types. You can use the Select clause to return only a single field from the data source. When you do this, the type of the collection returned is the type of ...
select new{Category=c, Products=ps}; 2、LINQ 类型 LINQ to Objects(或称LINQ to Collection),这是LINQ 的最基本功能,针对集合对象进行查询处理,包括基本的汇总与过滤都在这个功能内实现。 LINQ to SQL,这是LINQ 功能的SQL Server 数据库版本,通过LINQ 指令,可以直接查询SQL Server 数据库,而完全无须编写SQL...
DataListCommandEventArgs DataListCommandEventHandler DataListItem DataListItemCollection DataListItemEventArgs DataListItemEventHandler DataPager DataPagerCommandEventArgs DataPagerField DataPagerFieldCollection DataPagerFieldCommandEventArgs DataPagerFieldItem DataSourceSelectResultProcessingOptions DayNameFormat DayRenderEven...
我将构建一个只包含所需列的新数据表。。。 dim result = dt.AsEnumerable().[Select](Function(x) New With { Key .Col1 = x.Field(Of String)("Column1"), Key .Col2 = x.Field(Of String)("Column2") }).Tolist() 否则你可以
Console.WriteLine("Query result count: " + dynamicQuery.ToList().Count()); } /// <summary> /// This method creates based on input a query with different types. In the future there /// should be some select based on the binaryExpression to use (Equal, Greater, etc.) ...
convert sqlDatareader to list of objects convert string array to fileinfo array in c# Convert String Column To DateTime In DataTable Convert string into decimal with keeping decimal point Convert string into URL in C# Convert string to double without scientific notation Convert string to formula Co...
collections of objects are not retrieved until they areaccessed. This means that if I write a LINQ query to select an Order from the database it will not execute any statements to retrieve the OrderDetails until I attempt to access that child collection. This is a good thing because it sav...