다음을 통해 공유

Method-Based 쿼리 구문 예제: 변환

이 항목의 예제에서는 메서드 기반 쿼리 구문을 사용하여 ToArray, ToDictionary, ToList 메서드를 통해 AdventureWorks Sales Model을 쿼리하는 방법을 설명합니다. 이러한 예제에 사용된 AdventureWorks 판매 모델은 AdventureWorks 샘플 데이터베이스의 Contact, Address, Product, SalesOrderHeader 및 SalesOrderDetail 테이블에서 빌드됩니다.

이 항목의 예제에서는 다음과 같은 using/Imports 문을 사용합니다.

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

ToArray

예시

다음 예제에서는 메서드를 ToArray 사용하여 시퀀스를 배열로 즉시 평가합니다.

using (AdventureWorksEntities context = new AdventureWorksEntities())
{
    ObjectSet<Product> products = context.Products;

    Product[] prodArray = (
        from product in products
        orderby product.ListPrice descending
        select product).ToArray();

    Console.WriteLine("Every price from highest to lowest:");
    foreach (Product product in prodArray)
    {
        Console.WriteLine(product.ListPrice);
    }
}

Using context As New AdventureWorksEntities
    Dim products As ObjectSet(Of Product) = context.Products

    Dim prodArray As Product() = ( _
        From product In products _
        Order By product.ListPrice Descending _
        Select product).ToArray()

    Console.WriteLine("The list price from highest to lowest:")
    For Each prod As Product In prodArray
        Console.WriteLine(prod.ListPrice)
    Next
End Using

ToDictionary

예시

다음 예제에서는 ToDictionary 메서드를 사용하여 시퀀스 및 관련 키 식을 사전에 즉시 평가합니다.

using (AdventureWorksEntities context = new AdventureWorksEntities())
{
    ObjectSet<Product> products = context.Products;

    Dictionary<String, Product> scoreRecordsDict = products.
            ToDictionary(record => record.Name);

    Console.WriteLine($"Top Tube's ProductID: {scoreRecordsDict["Top Tube"].ProductID}");
}

Using context As New AdventureWorksEntities
    Dim products As ObjectSet(Of Product) = context.Products

    Dim scoreRecordsDict As Dictionary(Of String, Product) = _
        products.ToDictionary(Function(record) record.Name)

    Console.WriteLine("Top Tube's ProductID: {0}", _
        scoreRecordsDict("Top Tube").ProductID)
End Using

ToList

예시

다음 예제에서는 ToList 메서드를 사용하여 시퀀스를 List<T> 형식의 T로 평가하여 DataRow로 즉시 변환합니다.

using (AdventureWorksEntities context = new AdventureWorksEntities())
{
    ObjectSet<Product> products = context.Products;

    List<Product> query =
        (from product in products
         orderby product.Name
         select product).ToList();

    Console.WriteLine("The product list, ordered by product name:");
    foreach (Product product in query)
    {
        Console.WriteLine(product.Name.ToLower(CultureInfo.InvariantCulture));
    }
}

Using context As New AdventureWorksEntities
    Dim products As ObjectSet(Of Product) = context.Products

    Dim prodList As List(Of Product) = ( _
        From product In products _
        Order By product.Name _
        Select product).ToList()

    Console.WriteLine("The product list, ordered by product name:")
    For Each prod As Product In prodList
        Console.WriteLine(prod.Name.ToLower(CultureInfo.InvariantCulture))
    Next
End Using

참고하십시오