基于方法的查询语法示例：排序 (LINQ to Entities)

本主题中的示例演示如何使用 ThenBy 方法通过基于方法的查询语法查询 AdventureWorks 销售模型。这些示例中使用的 AdventureWorks 销售模型从 AdventureWorks 示例数据库中的 Contact、Address、Product、SalesOrderHeader 和 SalesOrderDetail 等表生成。

本主题中的示例使用下面的 using/Imports 语句：

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;

有关更多信息，请参见如何：在 Visual Studio 中创建 LINQ to Entities 项目。

ThenBy

示例

采用基于方法的查询语法的以下示例使用 OrderBy 和 ThenBy 以返回先按姓氏后按名字排序的联系人列表。

Using AWEntities As New AdventureWorksEntities

    Dim sortedContacts = AWEntities.Contact _
    .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

using (AdventureWorksEntities AWEntities = new AdventureWorksEntities())
{
    IQueryable<Contact> sortedContacts = AWEntities.Contact
        .OrderBy(c => c.LastName)
        .ThenBy(c => c.FirstName)
        .Select(c => c);

    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

示例

以下示例使用 OrderBy 和 ThenByDescending 方法以首先按标价排序，然后执行产品名称的降序排序。

Using AWEntities As New AdventureWorksEntities
    Dim products As ObjectQuery(Of Product) = AWEntities.Product

    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

using (AdventureWorksEntities AWEntities = new AdventureWorksEntities())
{
    ObjectQuery<Product> products = AWEntities.Product;

    IOrderedQueryable<Product> query = 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);
    }
}

另请参见

概念

基于方法的查询语法示例 (LINQ to Entities)