Mysql related query

Hello Friends,

I have a rails application where requirement is that, I want to display
books based on likes and expiry date…

I am using the following query

“select books., (select count() from likes where likes.book_id =
as ct
from books, book_expires where book_expires.book_id = order by
ASC, book_expires.end_at DESC”

And the output I am getting is on the bases of count not end_date…

Please let me know where I am getting wrong thanks…



First of all, if there are 2 models … then i think you got it wrong
… assuming you have

class Book < ActiveRecord::Base
has_many :likes
has_one :book_expire

class BookExpire < ActiveRecord::Base
belongs_to :book

class Like < ActiveRecord::Base
belongs_to :book

Then you could add " , :counter_cache => true " to the belongs_to
association (if needed add a likes_count field in the Book table)

if you do that …, then you could do a very easy query like

@books = Book.joins(:book_expire).all.order(’ likes_count ASC,
book_expires.end_at DESC’) # and i would add a limit ()

have a look here :
#23 Counter Cache Column - RailsCasts (even the move
uses rails 2.x … the concept and syntax is still valid )