Query Expression Syntax Examples: Ordering (LINQ to Entities)
The examples in this topic demonstrate how to use the OrderBy and OrderByDescending methods to query the AdventureWorks Sales Model using query expression syntax. The AdventureWorks Sales Model used in these examples is built from the Contact, Address, Product, SalesOrderHeader, and SalesOrderDetail tables in the AdventureWorks sample database.
The examples in this topic use the following using/Imports statements:
Option Explicit On
Option Strict On
Imports L2EExamplesVB.AdventureWorksModel
Imports System.Data.Objects
Imports System.Globalization
using System;
using System.Data;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data.Objects;
using AdventureWorksModel;
using System.Globalization;
For more information, see How to: Create a LINQ to Entities Project in Visual Studio.
OrderBy
Example
The following example uses OrderBy to return a list of contacts ordered by last name.
Using AWEntities As New AdventureWorksEntities
Dim contacts As ObjectQuery(Of Contact) = AWEntities.Contact
Dim sortedContacts = _
From contact In contacts _
Order By contact.LastName _
Select contact
Console.WriteLine("The sorted list of last names:")
For Each n As Contact In sortedContacts
Console.WriteLine(n.LastName)
Next
End Using
using (AdventureWorksEntities AWEntities = new AdventureWorksEntities())
{
ObjectQuery<Contact> contacts = AWEntities.Contact;
IQueryable<Contact> sortedNames =
from n in contacts
orderby n.LastName
select n;
Console.WriteLine("The sorted list of last names:");
foreach (Contact n in sortedNames)
{
Console.WriteLine(n.LastName);
}
}
Example
The following example uses OrderBy to sort a list of contacts by length of last name.
Using AWEntities As New AdventureWorksEntities
Dim contacts As ObjectQuery(Of Contact) = AWEntities.Contact
Dim sortedNames = _
From n In contacts _
Order By n.LastName.Length _
Select n
Console.WriteLine("The sorted list of last names (by length):")
For Each n As Contact In sortedNames
Console.WriteLine(n.LastName)
Next
End Using
using (AdventureWorksEntities AWEntities = new AdventureWorksEntities())
{
ObjectQuery<Contact> contacts = AWEntities.Contact;
IQueryable<Contact> sortedNames =
from n in contacts
orderby n.LastName.Length
select n;
Console.WriteLine("The sorted list of last names (by length):");
foreach (Contact n in sortedNames)
{
Console.WriteLine(n.LastName);
}
}
OrderByDescending
Example
The following example uses orderby… descending (Order By … Descending in Visual Basic), which is equivalent to the OrderByDescending method, to sort the price list from highest to lowest.
Using AWEntities As New AdventureWorksEntities
Dim products As ObjectQuery(Of Product) = AWEntities.Product
Dim sortedPrices = _
From product In products _
Order By product.ListPrice Descending _
Select product.ListPrice
Console.WriteLine("The list price from highest to lowest:")
For Each price As Decimal In sortedPrices
Console.WriteLine(price)
Next
End Using
using (AdventureWorksEntities AWEntities = new AdventureWorksEntities())
{
ObjectQuery<Product> products = AWEntities.Product;
IQueryable<Decimal> sortedPrices =
from p in products
orderby p.ListPrice descending
select p.ListPrice;
Console.WriteLine("The list price from highest to lowest:");
foreach (Decimal price in sortedPrices)
{
Console.WriteLine(price);
}
}
ThenBy
Example
The following example uses OrderBy and ThenBy to return a list of contacts ordered by last name and then by first name.
Using AWEntities As New AdventureWorksEntities
Dim contacts As ObjectQuery(Of Contact) = AWEntities.Contact
Dim sortedContacts = _
From contact In contacts _
Order By contact.LastName, contact.FirstName _
Select contact
Console.WriteLine("The list of contacts sorted by last name then by first name:")
For Each sortedContact As Contact In sortedContacts
Console.WriteLine(sortedContact.LastName + ", " + sortedContact.FirstName)
Next
End Using
using (AdventureWorksEntities AWEntities = new AdventureWorksEntities())
{
ObjectQuery<Contact> contacts = AWEntities.Contact;
IQueryable<Contact> sortedContacts =
from contact in contacts
orderby contact.LastName, contact.FirstName
select contact;
Console.WriteLine("The list of contacts sorted by last name then by first name:");
foreach (Contact sortedContact in sortedContacts)
{
Console.WriteLine(sortedContact.LastName + ", " + sortedContact.FirstName);
}
}
ThenByDescending
Example
The following example uses OrderBy… Descending, which is equivalent to the ThenByDescending method, to sort a list of products, first by name and then by list price from highest to lowest.
Using AWEntities As New AdventureWorksEntities
Dim products As ObjectQuery(Of Product) = AWEntities.Product
Dim query As IQueryable(Of Product) = _
From product In products _
Order By product.Name, product.ListPrice Descending _
Select product
For Each prod As Product In query
Console.WriteLine("Product ID: {0} Product Name: {1} List Price {2}", _
prod.ProductID, _
prod.Name, _
prod.ListPrice)
Next
End Using
using (AdventureWorksEntities AWEntities = new AdventureWorksEntities())
{
ObjectQuery<Product> products = AWEntities.Product;
IQueryable<Product> query =
from product in products
orderby product.Name, product.ListPrice descending
select product;
foreach (Product product in query)
{
Console.WriteLine("Product ID: {0} Product Name: {1} List Price {2}",
product.ProductID,
product.Name,
product.ListPrice);
}
}