public virtual void TestGroupByWithTwoPartKey()
{
var list = db.Orders.Where(o => o.CustomerID == "ALFKI").GroupBy(o => new { o.CustomerID, o.OrderDate }).Select(g => g.Sum(o => (o.CustomerID == "ALFKI" ? 1 : 1))).ToList();
AssertValue(6, list.Count);
}