Method-Based Query Syntax Examples: Conversion (LINQ to Entities)

The examples in this topic demonstrate how to use the ToArray, ToDictionary and ToList methods to query the AdventureWorks Sales Model using method-based query syntax. The AdventureWorks Sales Model used in these examples is built from the Contact, Address, Product, SalesOrderHeader, and SalesOrderDetail tables in the AdventureWorks sample database.

The examples in this topic use the following using/Imports statements:

using System;
using System.Data;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data.Objects;
using AdventureWorksModel;
using System.Globalization;

For more information, see How to: Create a LINQ to Entities Project in Visual Studio.

ToArray

Example

The following example uses the ToArray method to immediately evaluate a sequence into an array.

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

    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);
    }
}

ToDictionary

Example

The following example uses the ToDictionary method to immediately evaluate a sequence and a related key expression into a dictionary.

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

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

    Console.WriteLine("Top Tube's ProductID: {0}",
            scoreRecordsDict["Top Tube"].ProductID);
}

ToList

Example

The following example uses the ToList method to immediately evaluate a sequence into a List, where T is of type DataRow.

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

    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));
    }
}

See Also

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