HOW TO:排序資料 (Entity Framework)
本主題將說明如何排序查詢結果。 此範例會傳回依照 Contact.LastName 第一個字母的英文順序排序的 Contact 物件集合。 同時使用下列 Entity Framework 查詢技術顯示相同範例:
LINQ to Entities
Entity SQL with ObjectQuery<T>
Query builder methods of ObjectQuery<T>
本主題的範例根據 Adventure Works Sales Model。若要執行此主題中的程式碼,您必須已經將 Adventure Works Sales Model 加入到專案中,並設定您的專案使用 Entity Framework。如需詳細資訊,請參閱 HOW TO:使用實體資料模型精靈 (Entity Framework) 或 HOW TO:手動設定 Entity Framework 專案及 HOW TO:手動設定 Entity Framework 專案。
範例
以下是 LINQ to Entities 範例。
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);
}
}
以下是 Entity SQL 範例。
' 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);
}
}
以下是查詢產生器方法範例。
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);
}
}