Question

I need to group the table according to the Month in the table.

The query goes this way:

var query =
    from a in db.Dates
    from b in db.Facts
    where a.Count_Key == b.Date_key
    select new
    {
        a.Month,
        b.Fact_key
    };

From this query I try to group by Month

query = query.GroupBy(x => x.Month);
Grid1.DataSource = query;
Grid1.DataBind();

Then I get the following error which says:

Cannot implicitly convert IGrouping
int ? into IQueryable

Answer 1

You can do this:

var query2 = query.GroupBy(x => x.Month);
Grid1.DataSource = query2;
Grid1.DataBind();

The problem is caused because the var query is implicitly inferred from its usage. The query is of type IQueryable<SomeAnonymousType> and the GroupBy method returns an IQueryable<IGrouping<int?, SomeAnonymousType>>. Those are simply two different types.