How to find the record with the maximum price?

ruby-on-rails-3 activerecord max arel
Zabba picture Zabba · Jan 27, 2011 · Viewed 16.1k times · Source

This returns the maxium value, not the complete record:

self.prices.maximum(:price_field)

And currently, I find the record like this:

def maximum_price
  self.prices.find(:first, :conditions => "price = #{self.prices.maximum(:price_field)}" )
end

Is this the correct way ? Because the above needs two SQL statements to make it work, and it somehow does not feel right.

Ps. Additionally, I want that if more than one record has the same "maximum" value, then it should get the one with the latest updated_at value. So that would mean another SQL statement??

Pps. Does anyone know of a good or detailed reference for AREL and non-AREL things in Rails? The Rails Guide for ActiveRecord query is just not enough!

(I'm using Rails 3)

===UPDATE===

Using AREL I do the following:

self.prices.order("updated_at DESC").maximum(:price_field)

But this only gives the maximum value, not the complete record :(
Also, is the use of maximum() really AREL?

Answer

TK-421 picture TK-421 · Jan 27, 2011

How about something like this?

self.prices.order("price DESC").first

Related questions

How do you manually execute SQL commands in Ruby On Rails using NuoDB

I'm trying to manually execute SQL commands so I can access procedures in NuoDB. I'm using Ruby on Rails and I'm using the following command: ActiveRecord::Base.connection.execute("SQL query") The "SQL query" could be any SQL command. Like …

Read More
Check if record exists from controller in Rails

In my app a User can create a Business. When they trigger the index action in my BusinessesController I want to check if a Business is related to the current_user.id: If yes: display the business. If no: redirect …

Read More
Can you do greater than comparison on a date in a Rails 3 search?

I have this search in Rails 3: Note.where(:user_id => current_user.id, :notetype => p[:note_type], :date => p[:date]).order('date ASC, created_at ASC') But I need the :date => p[:date] condition to be …

Read More