쿼리 식 구문 예제: 제한(LINQ to Entities)

이 항목의 예제에서는 쿼리 식 구문을 사용하여 AdventureWorks Sales 모델을 쿼리하기 위해 Where 메서드를 사용하는 방법을 보여 줍니다. 이 예제에서 사용하는 AdventureWorks Sales 모델에서는 AdventureWorks 샘플 데이터베이스의 Contact, Address, Product, SalesOrderHeader 및 SalesOrderDetail 테이블을 사용합니다.

이 항목의 예제에서는 다음과 같은 using/Imports 문을 사용합니다.

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;

자세한 내용은 방법: Visual Studio에서 LINQ to Entities 프로젝트 만들기를 참조하십시오.

Where

예제

다음 예제에서는 모든 온라인 주문을 반환합니다.

Using AWEntities As New AdventureWorksEntities
    Dim orders As ObjectQuery(Of SalesOrderHeader) = AWEntities.SalesOrderHeader

    Dim onlineOrders = _
        From order In orders _
        Where order.OnlineOrderFlag = True _
        Select New With { _
           .SalesOrderID = order.SalesOrderID, _
           .OrderDate = order.OrderDate, _
           .SalesOrderNumber = order.SalesOrderNumber _
        }

    For Each onlineOrder In onlineOrders
        Console.WriteLine("Order ID: {0} Order date: {1:d} Order number: {2}", _
                onlineOrder.SalesOrderID, _
                onlineOrder.OrderDate, _
                onlineOrder.SalesOrderNumber)
    Next
End Using

using (AdventureWorksEntities AWEntities = new AdventureWorksEntities())
{
    ObjectQuery<SalesOrderHeader> orders = AWEntities.SalesOrderHeader;

    var onlineOrders =
        from order in orders
        where order.OnlineOrderFlag == true
        select new
        {
            SalesOrderID = order.SalesOrderID,
            OrderDate = order.OrderDate,
            SalesOrderNumber = order.SalesOrderNumber
        };

    foreach (var onlineOrder in onlineOrders)
    {
        Console.WriteLine("Order ID: {0} Order date: {1:d} Order number: {2}",
            onlineOrder.SalesOrderID,
            onlineOrder.OrderDate,
            onlineOrder.SalesOrderNumber);
    }
}

예제

다음 예제에서는 주문 수량이 2보다 크고 6보다 작은 주문을 반환합니다.

Using AWEntities As New AdventureWorksEntities
    Dim orders As ObjectQuery(Of SalesOrderDetail) = AWEntities.SalesOrderDetail

    Dim query = _
        From order In orders _
        Where order.OrderQty > 2 And order.OrderQty < 6 _
        Select New With { _
            .SalesOrderID = order.SalesOrderID, _
            .OrderQty = order.OrderQty _
        }

    For Each order In query
        Console.WriteLine("Order ID: {0} Order quantity: {1}", _
                order.SalesOrderID, order.OrderQty)
    Next
End Using

using (AdventureWorksEntities AWEntities = new AdventureWorksEntities())
{
    ObjectQuery<SalesOrderDetail> orders = AWEntities.SalesOrderDetail;

    var query =
        from order in orders
        where order.OrderQty > 2 && order.OrderQty < 6
        select new
        {
            SalesOrderID = order.SalesOrderID,
            OrderQty = order.OrderQty
        };

    foreach (var order in query)
    {
        Console.WriteLine("Order ID: {0} Order quantity: {1}",
            order.SalesOrderID, order.OrderQty);
    }
}

예제

다음 예제에서는 빨간색 제품을 모두 반환합니다.

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

    Dim query = _
        From product In products _
        Where product.Color = "Red" _
        Select New With { _
            .Name = product.Name, _
            .ProductNumber = product.ProductNumber, _
            .ListPrice = product.ListPrice _
        }

    For Each product In query
        Console.WriteLine("Name: {0}", product.Name)
        Console.WriteLine("Product number: {0}", product.ProductNumber)
        Console.WriteLine("List price: ${0}", product.ListPrice)
        Console.WriteLine("")
    Next
End Using

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

    var query =
        from product in products
        where product.Color == "Red"
        select new
        {
            Name = product.Name,
            ProductNumber = product.ProductNumber,
            ListPrice = product.ListPrice
        };

    foreach (var product in query)
    {
        Console.WriteLine("Name: {0}", product.Name);
        Console.WriteLine("Product number: {0}", product.ProductNumber);
        Console.WriteLine("List price: ${0}", product.ListPrice);
        Console.WriteLine("");
    }
}

예제

다음 예제에서는 Where 메서드를 사용하여 2003년 12월 1일 이후의 주문을 찾은 다음 order.SalesOrderDetail 탐색 속성을 사용하여 각 주문의 세부 사항을 가져옵니다.

Using AWEntities As New AdventureWorksEntities
    Dim orders As ObjectQuery(Of SalesOrderHeader) = AWEntities.SalesOrderHeader

    Dim query = _
        From order In orders _
        Where order.OrderDate >= New DateTime(2003, 12, 1) _
        Select order

    Console.WriteLine("Orders that were made after December 1, 2003:")
    For Each order In query
        Console.WriteLine("OrderID {0} Order date: {1:d} ", _
                order.SalesOrderID, order.OrderDate)
        For Each orderDetail In order.SalesOrderDetail
            Console.WriteLine("  Product ID: {0} Unit Price {1}", _
                orderDetail.ProductID, orderDetail.UnitPrice)
        Next
    Next
End Using

using (AdventureWorksEntities AWEntities = new AdventureWorksEntities())
{
    ObjectQuery<SalesOrderHeader> orders = AWEntities.SalesOrderHeader;

    IQueryable<SalesOrderHeader> query =
        from order in orders
        where order.OrderDate >= new DateTime(2003, 12, 1)
        select order;


    Console.WriteLine("Orders that were made after December 1, 2003:");
    foreach (SalesOrderHeader order in query)
    {
        Console.WriteLine("OrderID {0} Order date: {1:d} ",
            order.SalesOrderID, order.OrderDate);
        foreach (SalesOrderDetail orderDetail in order.SalesOrderDetail)
        {
            Console.WriteLine("  Product ID: {0} Unit Price {1}",
                orderDetail.ProductID, orderDetail.UnitPrice);
        }
    }
}

참고 항목

개념

쿼리 식 구문 예제(LINQ to Entities)