Ruby on Rails主动记录查询(.each,.collect,.map ......？)

Question

这是我的数据库中一个条目的一个示例:

Market id: 1, name: "Independence Park (Independently Run Farmers Market...", address: "3945 N. Springfield Ave., Chicago, IL", zipcode: "60618", created_at: "2013-01-01 21:22:24", updated_at: "2013-01-01 21:22:24"

我想要做的就是列出我数据库中所有条目的43个zipcodes.为什么这些查询不起作用？

1. Market.all.each { |m| m.zipcode }
2. Market.all.zipcode
3. • m = Market.all
   • m.each{ |m| m.zipcode }

谢谢!

Answer 1

如果你想要的只是一个邮政编码数组,我建议试试这个:

Market.pluck(:zipcode)