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Categories / C# Tutorial / LINQ
 

LINQ to DataSet

using System; using System.Collections.Generic; using System.Linq; using System.Data;             using System.Data.SqlClient;  using System.Data.Linq;       using System.Data.Common; using System.Text;     class Program     {         static void Main(string[] args)         {             SqlConnection thisConnection = new SqlConnection(                 @"Data Source=.\SQLEXPRESS;" +                 @"AttachDbFilename='NORTHWND.MDF';" +                 @"Integrated Security=True;Connect Timeout=30;User Instance=true");             SqlDataAdapter thisAdapter = new SqlDataAdapter("SELECT CustomerID, CompanyName FROM Customers", thisConnection);             SqlCommandBuilder thisBuilder = new SqlCommandBuilder(thisAdapter);             DataSet thisDataSet = new DataSet();             SqlDataAdapter custAdapter = new SqlDataAdapter("SELECT * FROM Customers", thisConnection);             SqlDataAdapter orderAdapter = new SqlDataAdapter("SELECT * FROM Orders", thisConnection);             custAdapter.Fill(thisDataSet, "Customers");             orderAdapter.Fill(thisDataSet, "Orders");             DataRelation custOrderRel = thisDataSet.Relations.Add("CustOrders",                  thisDataSet.Tables["Customers"].Columns["CustomerID"],                  thisDataSet.Tables["Orders"].Columns["CustomerID"]);             var customers = thisDataSet.Tables["Customers"].AsEnumerable();             var orders = thisDataSet.Tables["Orders"].AsEnumerable();             var preferredCustomers = from c in customers                 where c.GetChildRows("CustOrders").Length > 10                 select c;             foreach (var customer in preferredCustomers)             {                 Console.WriteLine(customer.GetChildRows("CustOrders").Length);                 Console.WriteLine(customer["CustomerID"]);             }             thisConnection.Close();         }     }