优化C语言中LINQ的简单用法#

我复制了我的代码的精简版本,最近重新编写了该版本,以使用LINQ访问数据库。

然而,在我看来,LINQ非常简单,可能会被优化很多,特别是在第90行,在foreach循环中有一个LINQ语句。

看看别人如何使用LINQ编写这个简单的任务,这真的很有帮助。事先谢谢!下面是我的源代码片段。

    // Model objects - these are to be populated from the database,
// which has identical fields and table names.
public class Element
{
    public Element()
    {
        Translations = new Collection<Translation>();
    }

    public int Id { get; set; }
    public string Name { get; set; }
    public Collection<Translation> Translations { get; set; }

    public class Translation
    {
        public int Id { get; set; }
        public string Title { get; set; }
        public string Content { get; set; }
        public Language Lang { get; set; }
    }
}
public class Language
{
    public int Id { get; set; }
    public string Name { get; set; }
    public string Code { get; set; }
}

// Stripped-down functions for adding and loading Element
// objects to/from the database:

public static class DatabaseLoader
{
    // Add method isn't too bulky, but I'm sure it could be optimised somewhere.
    public static void Add(string name, Collection<Translation> translations)
    {
        using (var db = DataContextFactory.Create<ElementContext>())
        {
            var dbElement = new Database.Element()
            {
                Name = name
            };
            db.Elements.InsertOnSubmit(dbElement);
            // Must be submit so the dbElement gets it's Id set.
            db.SubmitChanges();

            foreach (var translation in translations)
            {
                db.Translations.InsertOnSubmit(
                    new Database.Translation()
                        {
                            FK_Element_Id = dbElement.Id,
                            FK_Language_Id = translation.Lang.Id,
                            Title = translation.Title,
                            Content = translation.Content
                        });
            }

            // Submit all the changes outside the loop.
            db.SubmitChanges();
        }
    }

    // This method is really bulky, and I'd like to see the many separate linq
    // calls merged into one clever statement if possible (?).
    public static Element Load(int id)
    {
        using (var db = DataContextFactory.Create<ElementContext>())
        {
            // Get the database object of the relavent element.
            var dbElement =
                (from e in db.Elements
                 where e.Id == id
                 select e).Single();

            // Find all the translations for the current element.
            var dbTranslations =
                from t in db.Translations
                where t.Fk_Element_Id == id
                select t;

            // This object will be used to buld the model object.
            var trans = new Collection<Translation>();

            foreach (var translation in dbTranslations)
            {
                // Build up the 'trans' variable for passing to model object.
                // Here there is a linq statement for EVERY itteration of the
                // foreach loop... not good (?).
                var dbLanguage =
                    (from l in db.Languages
                     where l.Id == translation.FK_Language_Id
                     select l).Single();

                trans.Add(new Translation()
                    {
                        Id = translation.Id,
                        Title = translation.Title,
                        Content = translation.Content,
                        Language = new Language()
                            {
                                Id = dbLanguage.Id,
                                Name = dbLanguage.Name, 
                                Code = dbLanguage.Code
                            }
                    });
            }

            // The model object is now build up from the database (finally).
            return new Element()
                {
                    Id = id,
                    Name = dbElement.Name,
                    Translations = trans
                };
        }
    }
}