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 $"{fields[2]}, {fields[1]} {fields[0]}"; File.WriteAllLines("spreadsheet2.csv", q...
string[] lines = File.ReadAllLines("spreadsheet1.csv");// Create the query. Put field 2 first, then// reverse and combine fields 0 and 1 from the old fieldIEnumerable<string> query =fromlineinlinesletfields = line.Split(',')orderbyfields[2]select$"{fields[2]},{fields[1...
Order By OrderBy Order By … Descending OrderByDescending Order By (with multiple fields) ThenBy Order By … Descending (with multiple fields) ThenByDescending Select Select Skip Skip Take Take Take While TakeWhile Where WhereCreating SequencesThe...
public void LinqToSqlCount04() { var q = db.Products.Sum(p => p.UnitsOnOrder); Console.WriteLine(q); } 10.group by count() public void LinqToSqlJoin05() { var q = from c in db.Customers join o in db.Orders on c.CustomerID equals o.CustomerID into orders select new {c.Contact...
(tempQuery2).OrderBy(s => s); OutputQueryResults(nameMatchQuery, $"""Concat based on partial name match "{nameMatch}":"""); static void OutputQueryResults(IEnumerable<string> query, string message) { Console.WriteLine(Environment.NewLine + message); foreach (string...
Order By (with multiple fields)ThenBy Order By … Descending (with multiple fields)ThenByDescending SelectSelect SkipSkip TakeTake Take WhileTakeWhile WhereWhere Creating Sequences The Enumerable class provides several Shared methods that are not extension methods but exist for you to create new sequence...
Order Groups By (sort grouped data). Select (specify which fields or properties to return). Auto-sort (sort data records by a property that the user has selected). Auto-page (retrieve a subset of data records that were selected by the user). You can add conditions to the Where property...
5、 这个老外遇到的问题时,采用前面几个问题的综合解决办法还是遇到了order.Customer属性出不来,说明单向序列号还是有问题的,并且这个老外也没解决问题。 http://weblogs.asp.net/zeeshanhirani/archive/2008/07/14/entity-refs-not-getting-serialized-with-wcf-service.aspx ...
C# LINQ group by composite key We can group data by a composite key, consisting of multiple fields. Program.cs User[] users = [ new ("John", "Doe", "gardener"), new ("Jane", "Doe", "teacher"), new ("Roger", "Roe", "driver"), ...
However, sometimes getting all the fields is too wasteful so we want only certain fields, but still use our POCOs; something that is challenging for libraries that rely on object tracking, like LINQ to SQL. from p in db.Product orderby p.Name descending select new Product { Name = p.Na...