LINQ Query That Can Change But Can Group?

Question

This is the sort of thing I want to be able to do. I know you can qury linq results again, but because these results are in groups, I don't know how to. I think the best idea I can think of is to have a query to fetch everything, then do my if statement, then do another query that groups everything (so have 3 separate queries instead of 1). Any ideas on how best to do this sort of thing?

var Result =
    from a in DB.Table

    if(Something == 0)
    {
        where a.Value > 0
    }

    group a by a.Value into b
    select new {Group = b};

Answer 1

var result = from a in DB.Table;

if (Something == 0) 
{
 result = result.Where(r => r.Value > 0);
}

var finalResult = 
from a in result
group a by a.Value into b
select new {Group = b};

Answer 2

You can restrict Linq queries with "where" statements. Try exerimenting with that. something like:

var res = from c in db.table Where c.Id == 1 Select c

Answer 3

Would this do what you are looking for?

        var result =
        from a in DB.Table
        group a by a.Value into g
        where !Something.Equals(0) || g.Key > 0
        select new { Group = g };