Execute_grouped_calculation is one of those places where ActiveRecord forgets that it has ARel underpinnings, and assumes that the values provided to group_values are strings. This artificially hobbles otherwise functional code. This patch stops assuming that incoming values respond to to_sym, stops using string interpolation for table aliases on objects that support aliasing, and stops unnecessarily joining group_values on the relation. Additionally, it calls to_sql, if available, on objects sent to column_alias_for, in order to get a more reasonable alias string than a non-string's default to_str method.
[#4545 state:committed] Signed-off-by: Jeremy Kemper <firstname.lastname@example.org>