Ruby on Rails Active Record Query - counting records

Hi I'm new to rails and developing an application to pull results from database in preparation for charting. I have the following code in my controller:

@statistic = OutstandingWorkIndex.find_by_sql ["SELECT Result_Set.Set_Code, Request.Specimen_Number ,       
DATEDIFF('hh',Result_Set.Date_Time_Booked_In,current_timestamp) as HrsIn FROM iLabTP.Outstanding_Work_Index, iLabTP.Result_Set Result_Set, iLabTP.Request    
WHERE Outstanding_Work_Index.Request_Row_ID = Result_Set.Request_Row_ID and Outstanding_Work_Index.Request_Row_ID = Request.Request_Row_ID and Result_Set.Set_code=? 
order by Result_Set.Date_Time_Booked_In DESC", params[:set_code].upcase]

What I'd like to do is count the number of records returned in addition to the object from above which I then use to create and XML stream of paired values or use the google charts java script api in the view.

Do I need to issue commands like:

@statistic = OutstandingWorkIndex.find_by_sql ["SELECT Result_Set.Set_Code, Request.Specimen_Number , 
DATEDIFF('hh',Result_Set.Date_Time_Booked_In,current_timestamp) as HrsIn 
FROM iLabTP.Outstanding_Work_Index, iLabTP.Result_Set Result_Set, iLabTP.Request 
WHERE Outstanding_Work_Index.Request_Row_ID = Result_Set.Request_Row_ID and Outstanding_Work_Index.Request_Row_ID = Request.Request_Row_ID and Result_Set.Set_code=? 
order by Result_Set.Date_Time_Bo开发者_开发问答oked_In DESC", params[:set_code].upcase].**count**

And if so does this result in the query being reissued?

Thanks

You should do:

@size = @statistic.size

It's well explained here.