LINQ query returning multiple tables

Question

I have the following code:

MyDataContext dc = new MyDataContext();

IQueryable<Table1> q1 =
       from n in dc.Table1
       select n

What I want to be able to do is to join a second table, so:

var qry = 
      from n in dc.Table1
      join r in dc.Table2 on n.Key equals r.Key
      select new { n, r };

This returns me a type of IQueryable<anonymous> . What I now want to do is extract Table1 and Table2. For example (this obviously doesn't work):

IQueryable<Table1> q1 = qry.Table1
IQueryable<Table2> q2 = qry.Table2

Is there a way to do this?

Answer 1

You want to do something like this?

IQueryable<Table1> q1 = qry.Select(x => x.n);
IQueryable<Table2> q2 = qry.Select(x => x.r);

Answer 2

Sure there is:

IQueryable<Table1> q1 = qry.Select(a => a.n);
IQueryable<Table2> q2 = qry.Select(a => a.r);

Answer 3

You can define foreign keys to your tables (on the respective key fields) and add associations for them to your model clases (ideally via the LINQ-to-SQL designer).

Then you can do:

IQueryable<Table1> items1 = dc.Table1;

foreach (var item1 in items1)
{
    var items2 = item1.Table2s; // naming might differ
}

The drawback with doing it that way, is that, even with DataLoadOption s, L2S will make this very expensive. Querying Table2 for every row in the Table1 result set.