Ruby on Rails活動記錄查詢 - 計數記錄

Question

您好我是rails新手，開發一個應用程序以從數據庫中提取結果以準備繪製圖表。我有下面的代碼在我的控制器：

@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] 

我想要做的就是計算除了對象返回的記錄數從上面，然後我用它來創建和配對值的XML流或在視圖中使用谷歌圖表Java腳本API。

我是否需要發出如下命令：

@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].**count** 

如果是這樣就這樣的結果在查詢被補發？

感謝

Answer 1

你應該這樣做：

@size = @statistic.size 

這是很explained here。