Rails - 显示随机记录但不是当前记录

问题描述

在博客文章的末尾，我想显示指向另一篇随机文章的预告链接.显然，此链接不应该是当前帖子本身的预告片.

At the end of a blog post I would like to display a teaser link to another random post. Obviously this link should be NOT a teaser for the current post itself.

我已经知道如何选择随机帖子，但仍有可能是预告链接是当前帖子的链接.我想不通，我怎么能排除这种情况.

I figured already out how to choose a random post, but there is still the chance that the teaser link is a link to the current post. I couldn't figure out, how can I exclude this case.

这是我的控制器:

def show
    @post = Post.find(params[:id])
    @staff_pickrandom = Post.where(staff_pick:true).order("RANDOM()").limit(1)
end

我对 Rails 还很陌生，我仍然在为基本的东西苦苦挣扎.对不起，如果这是一个简单的.非常感谢您的帮助！！！

I am quite new to Rails and I am still struggling with basic stuff.Sorry, if this is an easy one. Thank you so much for helping out!!!

更新:我正在使用 Rails 3.2 和 "friendly_id" Gem.

UPDATE:I am using Rails 3.2 and the "friendly_id" Gem.

推荐答案

使用 order('RANDOM()').limit(1) 是正确的开始方式，因为最好让DB 选择随机记录，而不是获取大量 id，然后让 Ruby 从数组中采样.为了避免选择您当前使用的帖子，请使用 where.not 来排除该帖子

Using order('RANDOM()').limit(1) is the right way to start since it is better to let the DB choose a random record, than fetching a large set of ids, and letting Ruby sample from an array. In order to avoid choosing the post you are currently on use where.not to exclude that post

 Post.where(staff_pick: true).where.not(id: @post.id).order('RANDOM()').limit(1)

或

 Post.where(staff_pick: true).where('id != ?', @post.id).order('RANDOM()').limit(1)

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