Rails ActiveRecord group_by和sum db结果用于Lazy HighCharts

我是RoR / Ruby的新手，我正在使用Lazy High Charts gem根据一些数据库信息生成一些purdy图表。

我已经尝试过前一个问题中提供的答案，但我仍然对如何做到这一点感到困惑。

我需要按月/年计算amount_used，billed_amount和group（例如; 2012年8月）

最终结果类似于双轴图表，其中包含两个系列“已使用金额”和“成本”。此信息特定于某个account_id。

发票表

+---------------+--------------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +---------------+--------------+------+-----+---------+----------------+ | id | int(11) | NO | PRI | NULL | auto_increment | | account_id | int(11) | YES | | NULL | | | invoice_date | varchar(255) | YES | | NULL | | | amount_used | float | YES | | NULL | | | billed_amount | float | YES | | NULL | | | comments | text | YES | | NULL | | | created_at | datetime | NO | | NULL | | | updated_at | datetime | NO | | NULL | | +---------------+--------------+------+-----+---------+----------------+ 

控制器图表代码

 @account = Account.find(params[:id]) @invoices = Invoice.where("account_id = #{@account.id}").order("invoice_date DESC") @h = LazyHighCharts::HighChart.new('area') do |f| f.options[:chart][:defaultSeriesType] = "area" #Sample dates right now, should be the grouped_by :invoice_date f.xAxis( :categories => ['May', 'Jun', 'Jul'] ) f.yAxis([ { :title => { :text => "Amount Used" } }, { :title => { :text => "Cost" }, :opposite => true } ]) #Sample data right now, should be the summed amounts of the :amount_used correpsonding for each above grouped invoice_date f.series(:name => "Amount Used", :data => [100,300,500] ) #Sample data right now, should be the summed amounts of the :billed_amount correpsonding for each above grouped invoice date f.series(:name => "Cost", :yAxis => 1, :data => [200,400,600] ) end 

Answer 1

看起来你已经掌握了一切。 以下是从db中提取数据的方法：

 @aggregated_invoices = Invoice. where(:account_id => params[:id]). order("invoice_date DESC"). group("invoice_date"). select("DATE_FORMAT(invoice_date, '%Y-%m-01') AS invoice_date, sum(amount_used) AS amount_used, sum(billed_amount) AS billed_amount") # Then use these instead of sample data: @categories = @aggregated_invoices.map {|i| i.invoice_date.strftime("%b/%Y")} @amount_used_data = @aggregated_invoices.map(&:amount_used) @billed_amount_data = @aggregated_invoices.map(&:billed_amount)