Linq

Linq

Well standard LINQ is a new addition to .NET (it adds more dlls basically) that allows the programmer to query inline data as they probably would be used to doing with standard SQL-type syntax.

So where they may have had a query in a database or a SQL query string something like:

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SELECT * from Books WHERE QuatityInStock > 50 AND Price > 50.00

we would now write the following into as a valid LINQ query (assuming we have the relevant in memory data structure to support the query)

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var result =   from b Books   where b.QuatityInStock > 50 AND Price > 50.00   select b;

public static void LinqDemo()

{

Item it = new Item();

List items = new List();

it.Id = 1;

it.Price = 111;

items.Add(it);

it = new Item();

it.Id = 2;

it.Price = 222;

items.Add(it);

var iList = from i1 in items where i1.Price > 120 select i1;

foreach (var item in iList)

{

Console.WriteLine(item.Price);

}

}

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Imports System.Xml

Module Module1

Sub Main()

'Const path As New String=""

Dim s As New Stopwatch

s.Start()

Dim doc = XDocument.Load("C:\Documents and Settings\aakash\Desktop\Files\Customers.xml")

'LinqDisplayChildElements(doc)

LinqDistintOperator(doc)

'Dim xdoc As New XmlDocument()

'xdoc.Load("C:\Documents and Settings\aakash\Desktop\Files\Customers.xml")

'Dim nlist As XmlNodeList = xdoc.SelectNodes("Root/Customers/CompanyName")

'For Each Item As XmlNode In nlist

' Console.WriteLine(Item.InnerText)

'Next

s.Stop()

Console.WriteLine(s.ElapsedMilliseconds().ToString())

Console.ReadLine()

End Sub

Private Sub LinqDistintOperator(ByVal doc As XDocument)

Dim countries = From c In doc... Select name = c.Value Order By name Distinct

For Each c In countries

Console.WriteLine(c)

Next

'Dim faxes = From c In doc... Select fax = c.Value Order By fax

'For Each c In faxes

' Console.WriteLine(c)

'Next

End Sub

Private Sub LinqDisplayChildElements(ByVal doc As XDocument)

For Each Item As String In doc...

Console.WriteLine(Item.ToString())

Next

End Sub

End Module

http://msdn.microsoft.com/en-us/vbasic/bb688087.aspx

http://www.codeproject.com/KB/vista/LINQ_1.aspx

http://www.codeproject.com/KB/linq/LINQtoObjects_CS.aspx

http://msdn.microsoft.com/en-us/vbasic/bb738050.aspx#filtwhere -- this one is superb