Rails groupdate gem pg error

Question

我有一個Rails 3.2.14應用程序，我試圖用chartkick和groupdate gem來生成一些圖表。我已經安裝了這兩個寶石，我試圖在我的Call模型上從控制檯執行一些測試查詢。

Call.group_by_day(:created_at)

我拋出一個異常，並出現以下錯誤：

Call Load (8.8ms) SELECT "calls".* FROM "calls" WHERE (created_at IS NOT NULL) GROUP BY (DATE_TRUNC('week', (created_at::timestamptz - INTERVAL '6 day' - INTERVAL '0' hour) AT TIME ZONE 'America/Chicago') + INTERVAL '6 day' + INTERVAL '0' hour) AT TIME ZONE 'America/Chicago' 
ActiveRecord::StatementInvalid: PG::Error: ERROR: column "calls.id" must appear in the GROUP BY clause or be used in an aggregate function 
LINE 1: SELECT "calls".* FROM "calls" WHERE (created_at IS NOT NULL... 
      ^
: SELECT "calls".* FROM "calls" WHERE (created_at IS NOT NULL) GROUP BY (DATE_TRUNC('week', (created_at::timestamptz - INTERVAL '6 day' - INTERVAL '0' hour) AT TIME ZONE 'America/Chicago') + INTERVAL '6 day' + INTERVAL '0' hour) AT TIME ZONE 'America/Chicago 

有什麼我應該做的，使這項工作？是否有某種範圍需要創建才能完成這項工作？我是新來的寶石，所以任何幫助將不勝感激。

Answer 1

顯然我沒有正確調用它。

我需要撥打Call.group_by_day(:created_at).count才能完成此項工作。