LINQ to entities, method-based query, query expression syntax

This is the first time you have learned how to use LINQ to entities. Two sample codes are provided.

Method-based Query:

Using (adventureworksentities awentities = new adventureworksentities ())
{
Objectset <contact> contacts = awentities. contacts;
Objectset <salesorderheader> orders = awentities. salesorderheaders;

VaR query =
Contacts. select.pdf (
Contact => orders. Where (Order =>
(Contact. contactid = order. Contact. contactid)
& Amp; order. orderdate & gt; = new datetime (2002, 10, 1 ))
. Select (Order => New
{
Contactid = contact. contactid,
Lastname = contact. lastname,
Firstname = contact. firstname,
Orderid = order. salesorderid,
Orderdate = order. orderdate
}));

Foreach (VAR order in query)
{
Console. writeline ("Contact ID: {0} Name: {1}, {2} order ID: {3} order date: {4: d }",
Order. contactid, order. lastname, order. firstname,
Order. orderid, order. orderdate );
}
}

Query expression:

Using (adventureworksentities awentities = new adventureworksentities ())
{
Objectset <contact> contacts = awentities. contacts;
Objectset <salesorderheader> orders = awentities. salesorderheaders;

VaR query =
From contact in contacts
From Order in orders
Let Total = order. totaldue
Where contact. contactid = order. Contact. contactid
& Total> = 10000.0 m
Select New
{
Contactid = contact. contactid,
Lastname = contact. lastname,
Orderid = order. salesorderid,
Total
};

Foreach (VAR order in query)
{
Console. writeline ("Contact ID: {0} Last Name: {1} order ID: {2} Total: {3 }",
Order. contactid, order. lastname, order. orderid, order. Total );
}
}