Question

我有这个代码，你可以看到我有两个参数。我在一个表中创建了新字段，在另一个表中我更新了字段。

我需要将它们粘贴到MySQL中。一切都很酷，但我有一个问题：如何进行交易，因为我不想只在其中一个数据库中粘贴（更新或创建）。因为现在，如果我填充了一个参数，则表创建或更新，但我想将它们全部放在ONCE的数据库中。所以我的问题是......如何做交易以避免粘贴其中一个？

json_grid_params = ActiveSupport::JSON.decode(params[:grid_json]) 
json_form_params = ActiveSupport::JSON.decode(params[:form_json])  

   json_grid_params.each do |json_grid_params|   
    report      = Report.find(:all, :conditions => ["wat_id in (?)", json_grid_params["wat_id"].to_i])

        report.each do |r|
            rr = r.update_attributes(:percent_money => json_grid_params["percent_money"],
                                     :percent_item  => json_grid_params["percent_item"], 
                                     :trend         => json_grid_params["trend"])
        end

        form = FormAnswer.create(json_form_params)

更新

ActiveRecord::Base.transaction do
    json_grid_params = ActiveSupport::JSON.decode(params[:grid_json])
    json_form_params = ActiveSupport::JSON.decode(params[:form_json])  
           json_grid_params.each do |json_grid_params|   
        report = Report.find(:all, :conditions => ["wat_id in (?)", json_grid_params["wat_id"].to_i])
            report.each do |r|
                rr = r.update_attributes(:percent_money => json_grid_params["percent_money"], 
                          :percent_item  => json_grid_params["percent_item"], 
                          :trend         => json_grid_params["trend"])
            rr.save!
            form = FormAnswer.create(json_form_params)
            #form.save!
            end
        end 
end

并且在日志中出现此错误:(如果我将grid_params留空）

NoMethodError (undefined method `save!' for true:TrueClass):
  app/components/report_grid.rb:122:in `block (4 levels) in <class:ReportGrid>'
  app/components/report_grid.rb:118:in `each'
  app/components/report_grid.rb:118:in `block (3 levels) in <class:ReportGrid>'
  app/components/report_grid.rb:116:in `each'
  app/components/report_grid.rb:116:in `block (2 levels) in <class:ReportGrid>'
  app/components/report_grid.rb:113:in `block in <class:ReportGrid>'

Rendered /home/parallels/.rvm/gems/ruby-1.9.3-p0@rails314/gems/actionpack-3.1.4/lib/action_dispatch/middleware/templates/rescues/_trace.erb (0.7ms)
Rendered /home/parallels/.rvm/gems/ruby-1.9.3-p0@rails314/gems/actionpack-3.1.4/lib/action_dispatch/middleware/templates/rescues/_request_and_response.erb (0.8ms)
Rendered /home/parallels/.rvm/gems/ruby-1.9.3-p0@rails314/gems/actionpack-3.1.4/lib/action_dispatch/middleware/templates/rescues/diagnostics.erb within rescues/layout (2.8ms)

Answer 1

ActiveRecord::Base.transaction do
  ...
end

将在事务中包装块。如果某些模型具有不同的数据库连接，则在该特定类上调用事务以使事务在正确的连接上发生。

Rails 3 +交易：它们如何运作？

1 个答案: