Type of Iqueryable at runtime - asp.net-mvc

Question

I have a method which returns Iqueryable result, but the result is based on an if else condition, where if condition satisfies then I will use "AssetDetails" class object ,otherwise "UserandClientdetails" object.
Here is the code:
private IQueryable<?> GetAssetDetails(ShareViewModel item)
{
...
if (type == "Video")
{
if (type == "Video")
{
return from meta in my.Assets().OfType<Model.Video>()
join content in my.Contents() on meta.ContentId equals content.ID
join channel in my.Channels() on content.ChannelId equals channel.ID
where meta.ID == item.ID
select new AssetDetails
{
ContentTitle = content.Title,
ChannelName = channel.ChannelName,
...
};
}
else
{ return from meta in my.Assets().OfType<Model.Client>()
join country in db.Countries on meta.ResellerCountry equals country.ID
where meta.ID == item.ID
select new UserAndClientDetails
{
Name = meta.ResellerName,
UserName = meta.ResellerEmail,
..
};}
So how to decide type of Iqueyable here at runtime??

Answer 1

So, I was able to verify that this works, so I'll go ahead and post it as an answer.
You can return IQueryable instead of the generic IQueryable<>. That will accept any IQueryable<T>. However, IQueryable, since it has no direct inner type, is very limited. So, you'll still likely need to cast to IQueryable<> at some other point in your code to get anything done:
// Piece of code where you know you are working with `IQueryable<AssetDetails>`
IQueryable<AssetDetails> assetDetails = GetAssetDetails(someItem);
That's a little dangerous, though, as you're assuming that your code is working perfectly and the right type of thing is being returned. Better would be:
try
{
var assetDetails = (IQueryable<AssetDetails>)GetAssetDetails(someItem);
// do something with `assetDetails`
}
catch (InvalidCastException)
{
// recover gracefully
}

Answer 2

What about using a base class ?
public abstract class BaseDetails
{
// ...
}
public class AssetDetails : BaseDetails
{
// ...
}
public class UserAndClientDetails: BaseDetails
{
// ...
}
Then you method would be like :
private IQueryable<BaseDetails> GetAssetDetails(ShareViewModel item)
{
// return either IQueryable<AssetDetails> or IQueryable<UserAndClientDetails>
}