既然我们可以用任何我们想要的方式构造一个MongoDB，我们就可以这样做{products:[{date:"2010-09-08",data:{pageviews:23,timeOnPage:178}},{date:"2010-09-09",data:{pageviews:36,timeOnPage:202}}],brands:[{date:"2010-09-08",data:{pageviews:123,timeOnPage:210}},{date:"2010-09-09",data:{pageviews:61,timeOnPage:876}}]}随着我们日复一日地向其中添加数据，p