The On Blog

Last Rails 3.2 post. I swear.

I mentioned ActiveRecord::Relation#pluck in a previous post because it was one I was particularly excited about. After reading through the rest of the release notes I wanted to highlight a few of the other smaller changes I thought were interesting.

ActiveRecord

ActiveRecord::Relation#uniq

Client.select('DISTINCT name')

is now written

Client.select(:name).uniq

You can also revert the uniqueness with

Client.select(:name).uniq.uniq(false)

Don’t user LOWER for case insensitive searches on MySQL

When querying against our databases there are a bunch of times we don’t care about case. In the case of searching against an email address, a case insensitive search does exactly what we want it to. When you add the :case_sensitive => true to a validates_uniqueness_of it use to wrap that part of the query in a LOWER(). This sucked because it prevents MySQL from using an index. When you put this restriction on your email column and have to do this query every time you save a record. Since MySQL does case insensitive searches, ActiveRecord doesn’t worry about adding the LOWER() around the columns. Time saved all around!

rake db:drop drops both dev and test

rake db:create creates both the development and test databases. rake db:drop now drops the both development and test databases instead of just the development database.

ActiveView

namespace form_for

When you have multiple forms on one page for the same type of objects, you can get conflicting ids form elements. Problem solved with form namespaces.

<%= form_for(@offer, :namespace => 'namespace') do |f| %>
  <%= f.label :version, 'Version' %>:
  <%= f.text_field :version %>
<% end %>

The ids of the form elements have the namespace prepended with and underscore to the front of the original id.

ActiveSupport

Time Ranges

One of the things that I love most about Rails is ActiveSupport. And one of the things I love most about ActiveSupport is how it makes dealing with Time awesome and easy. They have added a few new convenience functions to help with date ranges:

• Time#all_day
• Time#all_week
• Time#all_month
• Time#all_quarter
• Time#all_year

You can use these with ActiveRecord queries like so:

Event.where(:created_at => Time.now.all_week)
Event.where(:created_at => Time.now.all_day)

Obviously there are a lot of other additions in 3.2, these are just the few that I know that I am going to have a use for. Enjoy.

§ 2 Responses to On 3.2

• Sammy says:

  January 30, 2012 at 11:17 am

  Last one? Keep them coming!

  Reply
• Les Fletcher says:

  January 30, 2012 at 4:01 pm

  Sammy, it’s the last one because there really isn’t anything else for me to say about it. There will be plenty more posts on other things though.

  Reply