How do you group by multiple columns in LINQ TO SQL?

Question

How do you group by multiple columns in LINQ TO SQL?

db.Table.GroupBy(a => a.column1.ToString() + a.column2.ToString())

It seems ugly and with poor performance, and I don't even know if it works. Which is the right way to do it?

Answer 1

try grouping by an anonymous type:

group by new { item.Col1, item.Col2 }

you'll then be able to access Key.Col1, etc