Category: LINQ

LINQ over untyped DataSets

This example comes from the AppDev (Exploring Visual Studio 2008 Using Visual C#)


DataSetr ds = FillDataset();
DataTable customerTable = ds.Tables["Customers"];

// DataTable does not implement IEnumerable
var cutomers = from c in customerTable.AsEnumerable()
               where c.Field("Country") == "USA"
               select new 
               {
                   CustomerID = c.Field("CustomerID"),
                   ContractName = c.Field("ContractName")
               {;

Lambda Expression and LINQ Extension

As I learn more about LINK I hope these things become more of an automatic choice rather than keeping notes… but for now I am stil new to LINQ:

You can use two different ways to retrieve items from a database. The first one is uses the DataContext to call the stored procedure and in a LINQ syntax:


NorthwindDataContext db = new NorthwindDataContext();
var results  = from item in db.CustOrderHist("category")
       where item.Total > 10
       select item;

and the second way is to use the extension with a lumbda expression:


results = db.CustOrderHist("category")
           .where (item => Item.Total > 10);

I still havn’t figure out which one has which benefits comparing the other way.