Question

Is it possible to return 2 selects with 1 Iqueryable?

I have a method that basically returns some records but I use it for paging so I also need to return the number of TOTAL records. It’s working, but rather than creating a concrete class with 2 properties (1 for the count and 1 for my select) I would rather stick with IQueryable but I am unsure if it is going to work.

Here’s an example what is returned from my COUNT:

 56

This refers to the amount records in the table.

And then my select returns a page with a number of records per page i.e.

ID      Name
32      John
33      Peter
34      David

so as you can see I have in effect 2 selects – 1 that returns the amount of records in the table and 1 that returns a subset of records from the table. Of course I am executing these 2 values as 2 separate queries in my method (C#) so I have 2 iqueryable vars in effect and I need to return both from the method.

So I wanted to keep my return method in line with the standard for a repository pattern i.e. returning IQueryable – but how would I do this?

I didn’t want to create 2 methods, 1 for returning the count and the other for returning the subset and as I say I didn’t want to change the return type to a concrete class (for example) that has 2 properties called Count and Data.

Answer 1

No, basically. LINQ-to-SQL itself supports multiple grids, but typically when calling a stored-proc, and not via IQueryable<T>. And since you don’t want to change the schema you can’t use a cheeky ExecuteQuery<T> with a dummy column. So no.

You could, however, do something like the following (which will of course mandate 2 round-trips to the server):

public static IQueryable<T> GetPage(this IQueryable<T> query,
    int skip, int take, out int count)
{
    count = query.Count();
    return query.Skip(skip).Take(take);
}