Rails的活动记录数在整个计算字段

Question

使用AREL/Rails的calculations我试图执行以下操作：

SELECT to_char(timestamp, 'YYYY-MM-DD') AS segment, COUNT(*) AS counter 
FROM pages 
GROUP BY segment 
ORDER BY segment 

我可以运行类似：

Page.order(FIELD).count(group: FIELD) 
{ a: 1, b: 4, c: 1 } 

不过，我可以”吨计算领域的工作。有什么想法吗？

Answer 1

想出了这个：

Page.count(:all, from: "(SELECT to_char(#{SEGMENT}, 'YYYY-MM-DD') AS segment FROM pages) AS pages", group: "segment", order: "segment") 
> SELECT COUNT(*) AS count_all, segment AS segment FROM (SELECT to_char(created_at, 'YYYY-MM-DD') AS segment FROM pages) AS pages GROUP BY segment ORDER BY segment