以方法為基礎的查詢語法範例:排序
本主題中的範例示範如何使用 ThenBy 方法,透過以方法為基礎的查詢語法來查詢 AdventureWorks 銷售模型。 這些範例中使用的 AdventureWorks Sales Model 是從 AdventureWorks 範例資料庫中的 Contact、Address、Product、SalesOrderHeader 和 SalesOrderDetail 資料表所建立。
此主題中的範例使用下列 using
/Imports
陳述式:
using System;
using System.Data;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data.Objects;
using System.Globalization;
using System.Data.EntityClient;
using System.Data.SqlClient;
using System.Data.Common;
Option Explicit On
Option Strict On
Imports System.Data.Objects
Imports System.Globalization
ThenBy
範例
下列以方法為基礎的查詢語法範例會使用 OrderBy 和 ThenBy 來傳回先依據姓氏再依據名字排序的連絡人清單。
using (AdventureWorksEntities context = new AdventureWorksEntities())
{
IQueryable<Contact> sortedContacts = context.Contacts
.OrderBy(c => c.LastName)
.ThenBy(c => c.FirstName);
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);
}
}
Using context As New AdventureWorksEntities
Dim sortedContacts = context.Contacts _
.OrderBy(Function(c) c.LastName) _
.ThenBy(Function(c) c.FirstName) _
.Select(Function(c) c)
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
ThenByDescending
範例
下列範例會使用 OrderBy 和 ThenByDescending 方法,先依據標價排序,然後再執行產品名稱的遞減排序。
using (AdventureWorksEntities context = new AdventureWorksEntities())
{
IOrderedQueryable<Product> query = context.Products
.OrderBy(product => product.ListPrice)
.ThenByDescending(product => product.Name);
foreach (Product product in query)
{
Console.WriteLine("Product ID: {0} Product Name: {1} List Price {2}",
product.ProductID,
product.Name,
product.ListPrice);
}
}
Using context As New AdventureWorksEntities
Dim products As ObjectSet(Of Product) = context.Products
Dim query As IOrderedQueryable(Of Product) = products _
.OrderBy(Function(prod As Product) prod.ListPrice) _
.ThenByDescending(Function(prod As Product) prod.Name)
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