CODEWITHSUNDEEP
ruby-on-rails
Dan
Dan

Reputation: 85

Previous article in Rails App

I implemented a prev/next post method in my blog rails application but the previous method is giving errors. Not sure what to 

# app/models/post.rb

def next
  Post.where("id > ?", id).limit(1).first
end

def prev
  Post.where("id < ?", id).limit(1).first
end

Then in my view:

# app/views/posts/show.html.erb

<%= link_to "Prev Post", @post.prev %>
<%= link_to "Next Post", @post.next %>

"Next" works perfectly, but "prev" seems to link to the very first post written instead of the one before it. What am I doing wrong?

Upvotes: 1

Views: 28

Answers (2)

Michael Giovanni Pumo
Michael Giovanni Pumo

Reputation: 14784

Try using .last

def prev
  Post.where("id < ?", id).limit(1).last
end

Upvotes: 0

Sergio Tulentsev
Sergio Tulentsev

Reputation: 230481

It's because you didn't specify sort order. I wouldn't be suprised if next also didn't work (sometimes). When you rely on order of things, specify it explicitly.

def next
  Post.where("id > ?", id).order(id: :asc).limit(1).first
end

def prev
  Post.where("id < ?", id).order(id: :desc).limit(1).first
end

Upvotes: 1

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