BreedId in the Dog table is obviously a foreign key to the corresponding row in the Breed table. If you've got your database set up properly, LINQ to SQL should automatically create an association between the two tables. The resulting Dog class will have a Breed property, and the Breed class should have a Dogs collection. Setting it up this way, you can still return IEnumerable<Dog>, which is an object that includes the breed property. The only caveat is that you need to preload the breed object along with dog objects in the query so they can be accessed after the data context has been disposed, and (as another poster has suggested) execute a method on the collection that will cause the query to be performed immediately (ToArray in this case):

public IEnumerable<Dog> GetDogs()
{
    using (var db = new DogDataContext(ConnectString))
    {
        db.LoadOptions.LoadWith<Dog>(i => i.Breed);
        return db.Dogs.ToArray();
    }

}

然后，访问每只狗的品种是微不足道的:

foreach (var dog in GetDogs())
{
    Console.WriteLine("Dog's Name: {0}", dog.Name);
    Console.WriteLine("Dog's Breed: {0}", dog.Breed.Name);        
}

只是补充一下我的意见:-) 我最近学习了一种处理匿名对象的方法。它只能在针对。net 4框架时使用，并且只能在添加对System.Web.dll的引用时使用，但它非常简单:

...
using System.Web.Routing;
...

class Program
{
    static void Main(string[] args)
    {

        object anonymous = CallMethodThatReturnsObjectOfAnonymousType();
        //WHAT DO I DO WITH THIS?
        //I know! I'll use a RouteValueDictionary from System.Web.dll
        RouteValueDictionary rvd = new RouteValueDictionary(anonymous);
        Console.WriteLine("Hello, my name is {0} and I am a {1}", rvd["Name"], rvd["Occupation"]);
    }

    private static object CallMethodThatReturnsObjectOfAnonymousType()
    {
        return new { Id = 1, Name = "Peter Perhac", Occupation = "Software Developer" };
    }
}

为了能够添加对System.Web.dll的引用，你必须遵循rushonerok的建议:确保你的[项目的]目标框架是“。NET Framework 4“不是”。NET Framework 4客户端配置文件”。

这并没有完全回答你的问题，但谷歌根据关键字引导我到这里。这是从列表中查询匿名类型的方法:

var anon = model.MyType.Select(x => new { x.Item1, x.Item2});

如果你在你的数据库中有一个关系设置，在BreedId上有一个外键约束，你还没有得到吗?

所以我现在可以调用:

internal Album GetAlbum(int albumId)
{
    return Albums.SingleOrDefault(a => a.AlbumID == albumId);
}

在调用它的代码中:

var album = GetAlbum(1);

foreach (Photo photo in album.Photos)
{
    [...]
}

在你的实例中，你会调用像dog。breed。breedname这样的东西-正如我说的，这依赖于你的数据库是用这些关系建立的。

正如其他人所提到的，如果存在数据库调用问题，DataLoadOptions将有助于减少数据库调用。

如果主要的想法是让SQL选择语句发送到数据库服务器只有必需的字段，而不是所有的实体字段，那么你可以这样做:

public class Class1
{
    public IList<Car> getCarsByProjectionOnSmallNumberOfProperties()
    {

        try
        {
            //Get the SQL Context:
            CompanyPossessionsDAL.POCOContext.CompanyPossessionsContext dbContext 
                = new CompanyPossessionsDAL.POCOContext.CompanyPossessionsContext();

            //Specify the Context of your main entity e.g. Car:
            var oDBQuery = dbContext.Set<Car>();

            //Project on some of its fields, so the created select statment that is
            // sent to the database server, will have only the required fields By making a new anonymouse type
            var queryProjectedOnSmallSetOfProperties 
                = from x in oDBQuery
                    select new
                    {
                        x.carNo,
                        x.eName,
                        x.aName
                    };

            //Convert the anonymouse type back to the main entity e.g. Car
            var queryConvertAnonymousToOriginal 
                = from x in queryProjectedOnSmallSetOfProperties
                    select new Car
                    {
                        carNo = x.carNo,
                        eName = x.eName,
                        aName = x.aName
                    };

            //return the IList<Car> that is wanted
            var lst = queryConvertAnonymousToOriginal.ToList();
            return lst;

        }
        catch (Exception ex)
        {
            System.Diagnostics.Debug.WriteLine(ex.ToString());
            throw;
        }
    }
}

不能直接返回匿名类型，但可以通过泛型方法对它们进行循环。大多数LINQ扩展方法也是如此。这里没有什么神奇之处，虽然看起来它们会返回匿名类型。如果参数是匿名的结果也可以是匿名的。

var result = Repeat(new { Name = "Foo Bar", Age = 100 }, 10);

private static IEnumerable<TResult> Repeat<TResult>(TResult element, int count)
{
    for(int i=0; i<count; i++)
    {
        yield return element;
    }
}

下面是一个基于原始问题代码的示例:

var result = GetDogsWithBreedNames((Name, BreedName) => new {Name, BreedName });


public static IQueryable<TResult> GetDogsWithBreedNames<TResult>(Func<object, object, TResult> creator)
{
    var db = new DogDataContext(ConnectString);
    var result = from d in db.Dogs
                    join b in db.Breeds on d.BreedId equals b.BreedId
                    select creator(d.Name, b.BreedName);
    return result;
}