How do you cast an IEnumerable<t> or IQueryable<t> to an EntitySet<t>?

.net, c#, linq

Solution

you can construct your entity set from a IEnumerable using a helper class, something like:

public static class EntityCollectionHelper
{
    public static EntitySet<T> ToEntitySet<T>(this IEnumerable<T> source) where T:class
    {
        EntitySet<T> set = new EntitySet<T>();
        set.AddRange(source);
        return set;
    }
}

and use it like so :

PageContents = (from pc in el.Elements()
                                where pc.Name.LocalName == "revision"
                                select new PageContent()
                                {
                                   Content = pc.Elements().Where(e => e.Name.LocalName=="text").First().Value,
                                   Username = pc.Elements().Where(e => e.Name.LocalName == "contributor").First().Elements().Where(e => e.Name.LocalName == "username").First().Value,
                                   DateTime = DateTime.Parse(pc.Elements().Where(e => e.Name.LocalName == "timestamp").First().Value)
                                }).ToEntitySet()

Problem

In this situation I am trying to perform a data import from an XML file to a database using LINQ to XML and LINQ to SQL. Here's my LINQ data model: ``` public struct Page { public string Name; public char Status; public EntitySet<PageContent> PageContents; } public struct PageContent { public string Content; public string Username; public DateTime DateTime; } ``` Basically what I'm trying to do is write a query that will give me a data structure that I can just submit to my LINQ Data Context. ``` IEnumerable<Page> pages = from el in doc.Descendants() where el.Name.LocalName == "page" select new Page() { Name = el.Elements().Where(e => e.Name.LocalName == "title").First().Value, Status = 'N', PageContents = (from pc in el.Elements() where pc.Name.LocalName == "revision" select new PageContent() { Content = pc.Elements().Where(e => e.Name.LocalName=="text").First().Value, Username = pc.Elements().Where(e => e.Name.LocalName == "contributor").First().Elements().Where(e => e.Name.LocalName == "username").First().Value, DateTime = DateTime.Parse(pc.Elements().Where(e => e.Name.LocalName == "timestamp").First().Value) }).ToList() }; ``` The problem is in the sub-query. I have to somehow get my object collection into the EntitySet container. I can't cast it (oh lord how I've tried) and there's no EntitySet() constructor that would seem to help. So, can I write a LINQ query that will populate the EntitySet<PageContent> data with my IEnumerable<Page> data?

Original source