Ruby on Rails中使用弹拨值 [英] Using Plucked Values in Ruby on Rails

问题描述

给定一个名为相册样板，我想用我掐了值。首先，我想尝试打印值。我怎样才能做到这一点？这是我目前的code：

Given a model named Album, I want to use the values I pluck. For starters, I want to try to print the values. How can I do this? Here is my current code:

my_arr = Album.where(title: "Greatest Hits", artist: "The Beatles").pluck(:publisher, :year_published)

puts my_arr[0][0].to_a

为了让事情更简单，我怎么会检索任何价值可言，这样我就可以把它变成一个正常的变量？

To make things even simpler, how would I retrieve any value at all, so that I could place it into a normal variable?

我用Rails 4 sqlite3的。

I'm using Rails 4 with SQLite3.

推荐答案

勇气 已经返回数组 - 你不需要操作的输出

pluck already returns an array - you do not need to manipulate the output of

Album
  .where(title: "Greatest Hits", artist: "The Beatles")
  .pluck(:publisher, :year_published)

以任何方式 - 它是一个数组。在这种情况下，2个元素的数组的数组

in any way - it is an array. In this case an array of 2-element arrays.

如果你有一个空数组 - 我保证你只是没有满足其中，条件的任何记录。这可能是一个小错字在标题结果的或艺术家的名字损失（这开始被无关的问题）。如果你确信你有符合过滤数据库对象 - 一定要仔细检查是否有错别字，因为你的查询是正确的。

If you have an empty array - I guarantee you just do not have any records meeting the where conditions. It might be a result of a tiny typo in title's or artist's name whatsoever (which starts to be unrelated to question). If you are sure you have database objects that meet the filter - make sure to double check for typos, because your query is correct.

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