Cómo: Ordenar datos (Entity Framework)
En este tema se describe cómo ordenar los resultados de una consulta. Este ejemplo devuelve una colección de objetos Contact ordenados alfabéticamente por la primera letra del apellido de Contact.LastName. Se muestra el mismo ejemplo con las siguientes tecnologías de consulta de Entity Framework :
LINQ to Entities
Entity SQL con ObjectQuery<T>
Métodos del generador de consultas de ObjectQuery<T>
El ejemplo de este tema se basa en el modelo AdventureWorks Sales. Para ejecutar el código de este tema, debe haber agregado el modelo AdventureWorks Sales al proyecto y haber configurado el proyecto para que use Entity Framework. Para obtener más información, vea Cómo: Usar el Asistente para Entity Data Model (Entity Framework) o Cómo: Configurar manualmente un proyecto de Entity Framework y Cómo: Definir manualmente un modelo Entity Data Model (Entity Framework).
Ejemplo
A continuación se muestra el ejemplo de LINQ to Entities .
Using context As New AdventureWorksEntities()
' Define a query that returns a list
' of Contact objects sorted by last name.
Dim sortedNames = From n In context.Contacts _
Order By n.LastName _
Select n
Console.WriteLine("The sorted list of last names:")
For Each name As Contact In sortedNames
Console.WriteLine(name.LastName)
Next
End Using
using (AdventureWorksEntities context =
new AdventureWorksEntities())
{
// Define a query that returns a list
// of Contact objects sorted by last name.
var sortedNames =
from n in context.Contacts
orderby n.LastName
select n;
Console.WriteLine("The sorted list of last names:");
foreach (Contact name in sortedNames)
{
Console.WriteLine(name.LastName);
}
}
A continuación se muestra el ejemplo de Entity SQL .
' Define the Entity SQL query string that returns
' Contact objects sorted by last name.
Dim queryString As String = "SELECT VALUE contact FROM Contacts AS contact Order By contact.LastName"
Using context As New AdventureWorksEntities()
' Define an ObjectQuery that returns a collection
' of Contact objects sorted by last name.
Dim query As New ObjectQuery(Of Contact)(queryString, context)
Console.WriteLine("The sorted list of last names:")
For Each name As Contact In query.Execute(MergeOption.AppendOnly)
Console.WriteLine(name.LastName)
Next
End Using
// Define the Entity SQL query string that returns
// Contact objects sorted by last name.
string queryString = @"SELECT VALUE contact FROM Contacts AS contact
Order By contact.LastName";
using (AdventureWorksEntities context =
new AdventureWorksEntities())
{
// Define an ObjectQuery that returns a collection
// of Contact objects sorted by last name.
ObjectQuery<Contact> query =
new ObjectQuery<Contact>(queryString, context);
Console.WriteLine("The sorted list of last names:");
foreach (Contact name in query.Execute(MergeOption.AppendOnly))
{
Console.WriteLine(name.LastName);
}
}
A continuación se muestra el ejemplo del método del generador de consultas.
Using context As New AdventureWorksEntities()
' Define an ObjectQuery that returns a collection
' of Contact objects sorted by last name.
Dim query As ObjectQuery(Of Contact) = context.Contacts.OrderBy("it.LastName")
Console.WriteLine("The sorted list of last names:")
For Each name As Contact In query.Execute(MergeOption.AppendOnly)
Console.WriteLine(name.LastName)
Next
End Using
using (AdventureWorksEntities context =
new AdventureWorksEntities())
{
// Define an ObjectQuery that returns a collection
// of Contact objects sorted by last name.
ObjectQuery<Contact> query =
context.Contacts.OrderBy("it.LastName");
Console.WriteLine("The sorted list of last names:");
foreach (Contact name in query.Execute(MergeOption.AppendOnly))
{
Console.WriteLine(name.LastName);
}
}