查詢運算式語法範例：元素運算子 (LINQ to Entities)
本主題中的範例將示範如何使用 First 方法，透過查詢運算式語法來查詢 AdventureWorks Sales Model。 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。
此主題中的範例將使用下列 using/Imports 陳述式：
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;
如需詳細資訊，請參閱 HOW TO：在 Visual Studio 中建立 LINQ to Entities 專案。
First
範例
下列範例會使用 First 方法來傳回名字為 "Brooke" 的第一位連絡人。
Using AWEntities As New AdventureWorksEntities
Dim contacts As ObjectQuery(Of Contact) = AWEntities.Contact
Dim query As Contact = ( _
From cont In contacts _
Where cont.FirstName = "Brooke" _
Select cont).First()
Console.WriteLine("ContactID: " & query.ContactID)
Console.WriteLine("FirstName: " & query.FirstName)
Console.WriteLine("LastName: " & query.LastName)
End Using
using (AdventureWorksEntities AWEntities = new AdventureWorksEntities())
{
ObjectQuery<Contact> contacts = AWEntities.Contact;
Contact query = (
from contact in contacts
where contact.FirstName == "Brooke"
select contact)
.First();
Console.WriteLine("ContactID: " + query.ContactID);
Console.WriteLine("FirstName: " + query.FirstName);
Console.WriteLine("LastName: " + query.LastName);
}