So in Rails 4 the long desired feature to use not queries has been added.
Article.where.not(title: 'Rails 3')
Has similar support been added for or queries, or are they planning to make it. I couldn't find anything by browsing through the release notes.
Obviously I tried
Article.where(title: 'Rails 3').or(title: 'Rails 4')
But that does not work.
Article.where(title: ['Rails 3', 'Rails 4'])
is how you'd do that in Active Record.
It's not possible to replicate any arbitrary SQL query using "Rails-y" syntax. But you can always just pass in literal sql.
So you could also do:
Article.where("articles.title = 'Rails 3' OR articles.title = 'Rails 4'")
This now works in Rails 5:
Article.where(title: 'Rails 3').or(Article.where(title: 'Rails 4'))
Code example in Rails's source.
The most common alternative is already answer by #gregates
Recently there has been pull request in rails source
Add #any_of query method to active_record
Which adds or functionality to activerecord
the contributor has already created a gem incase its not accepted
its rails 3.2 and 4 compatible
https://github.com/oelmekki/activerecord_any_of
I havent tried it yet but soon wish to use it looks good to me.
I know that this is an old thread, but anyone else looking for a solution to this problem might find this code helpful:
Article.where(title: ["Rails 3", "Rails 4"])
Maybe that will help you get someone going in the right direction without having to risk sql injection.
It seems that the rails master branch is now supporting OR queries. https://github.com/rails/rails/pull/16052
I assume it will be in the framework with the next major release.
Rails 5 will support it but you can use this backport for Rails 4.2 : https://github.com/Eric-Guo/where-or
Related
Hello every one I'm new to ruby on rails. I go through the following code in which I'm told that database schema is being loaded through this code:
Account.current = Question.find(2)
Question.last
I'm unable to understand about how schema is being loaded. what this code is actually doing. Please help
Start with Rails Guides (Active Record). Here is the documentation.
Also, look at AREL. Here is the link to it on GitHub.
This article explains how arel converts ruby queries into sql statements.
I have been using the seedbank gem to give my Rails seeds some structure (i.e. environment specific seed folders, one seed file per model, order dependencies etc.)
Now I came across the seed_fu gem which among other things makes it easy and expressive to say "seed these records, and if one with that id exists, update the other fields". E.g:
Category.seed(:id,
{ :id => 1, :name => "Food" },
{ :id => 2, :name => "Drink" }
)
I can achieve the same result with some cumbersome ActiveRecord calls in my seed files, but I would much rather use the nice syntax provided by seed_fu. Additionally, I want to keep using the features seedbank gives me. Another rationale is that I may migrate only part of my seed files to the other syntax and that it makes no sense to use two rake commands side by side.
If I just put the above code in my db/seeds/categories.seeds.rb file and run rake db:seed:categories i get the error undefined method 'seed'. I guess I would somehow need to import the seed method from SeedFu:ActiveRecordExtension, but I don't know how.
I'm on Rails 3.2.13 and using the newest version of seed_fu straight from the github repo.
Short answer: seed_fu and seedbank work together without any problem.
I was using the zeus gem and hadn't reloaded my Rails environment so the seed_fu DSL just wasn't loaded yet.
(I will leave the question here for anyone wondering if you can use these gems together. TL;DR: yes.)
I have a Rails 2 app that uses 2dc_jqgrid and thus squirrel to build jqgrids.
Now looking to move to Rails 3, but I see that squirrel is not coming over.
[ http://robots.thoughtbot.com/post/687890317/the-road-to-rails-3 ]
It seems that squirrel is mainly used for paginate by 2dc_jqgrid.
There are some alternate branches for 2dc_jqgrid - some even labelled rails3 - hopefully one of them will do.
So, any tips/clues on the best way to find the right branch...
Thanks in advance, Chris.
rails3 compatible jqgrid plugins:
https://github.com/doabit/jqgrid-rails3
https://github.com/davebaldwin/jqgrid-rails3 (detailed usage)
https://github.com/springbok/jqgrid-rails3
Looks like this fork might be Rails 3 compatible...
https://github.com/darmou/2dc_jqgrid
I am using the geokit gem and plugin with rails 3. It seems there is a known issue with them, which can be seen here http://github.com/andre/geokit-rails/issues#issue/15
Now, I tried to follow the solution provided at the bottom. I pasted that function definition, at the end of the file, just above acts_as_mapable, and just after the first time it was called, but nothing happened each time.
Any idea what else can be done?
Thanks
I ran into similar problems upgrading my app to rails 3. I'm still using Geokit for geocoding but Active Record scopes for distance based database queries. It's pretty convenient, and you still get all of the Active Record 3 goodness. Here's an example from my User model:
scope :near, lambda{ |*args|
origin = *args.first[:origin]
if (origin).is_a?(Array)
origin_lat, origin_lng = origin
else
origin_lat, origin_lng = origin.lat, origin.lng
end
origin_lat, origin_lng = deg2rad(origin_lat), deg2rad(origin_lng)
within = *args.first[:within]
{
:conditions => %(
(ACOS(COS(#{origin_lat})*COS(#{origin_lng})*COS(RADIANS(users.lat))*COS(RADIANS(users.lng))+
COS(#{origin_lat})*SIN(#{origin_lng})*COS(RADIANS(users.lat))*SIN(RADIANS(users.lng))+
SIN(#{origin_lat})*SIN(RADIANS(users.lat)))*3963) <= #{within}
),
:select => %( users.*,
(ACOS(COS(#{origin_lat})*COS(#{origin_lng})*COS(RADIANS(users.lat))*COS(RADIANS(users.lng))+
COS(#{origin_lat})*SIN(#{origin_lng})*COS(RADIANS(users.lat))*SIN(RADIANS(users.lng))+
SIN(#{origin_lat})*SIN(RADIANS(users.lat)))*3963) AS distance
)
}
}
Here's a blog post with a little more detail on the subject: http://stcorbett.com/code/distance-queries-with-rails-3-without-geokit/
jlecour's port to rails 3 should solve any issues you were having last year.
Make sure you're using mysql or postgres if you're doing distance calculations.
After trouble installing the geokit-rails3 gem on Rails 3.1 I moved to the geocoder gem. It has distance calculation as well (be sure to not forget the s in #your_model.nearby*s*(5)). There is also a Railscast.
Here is port of geokit to rails 3, incomplete through:
https://github.com/jlecour/geokit-rails3
For those still having trouble with geokit, i moved on to using mongodb... which has inbuilt distance search n all...
Hey Amit, Not sure if you sorted this out yet but I'll tell you what I did just in case.
I forked andre's geokit-rails source and then cloned it locally and added the code from this gist at line 34 of lib/geokit-rails/acts-as-mappable.rb, just after the line that reads module ClassMethods # :nodoc:.
Then I commited those changes back to my forked repo on github and used my fork to install the source as a plugin to my rails 3 app. That seemed to work straight away, but make sure you have the acts_as_mappable line added to whatever model you are wanting to do distance calculations on and make sure you have two float columns on that db named :lat and :lng.
I am a beginner in Rails. I use 2.3.X.
I just saw Rails 3 is pre-released [edit: now in release candidate!]. I will most probably eventually switch to it.
What are the common coding habits in 2.3 I should not take, so that the switch is as smooth as possible ?
Edit:
I've done my homework and read the Release notes. But they are far from clear for the most crucial points, for example :
1.5 New APIs
Both the router and query interface have seen significant, breaking changes. There is a backwards compatibility layer that is in place and will be supported until the 3.1 release.
This is not comprehensive enough for a beginner like me. What will break ? What could I do already in 2.3.X to avoid having troubles later ?
Looking at my personal coding habits (I have been using Rails since 1.2.x), here's a list of API changes you can anticipate according to Rails 3 release notes.
find(:all)
Avoid the usage of:
Model.find(:all)
Model.find(:first)
Model.find(:last)
in favour of:
Model.all
Model.first
Model.last
Complex queries
Avoid the composition of complex queries in favor of named scopes.
Anticipate Arel
Rails 3 offers a much cleaner approach for dealing with ActiveRecord conditions and options. You can anticipate it creating custom named scopes.
class Model
named_scope :limit, lambda { |value| { :limit => value }}
end
# old way
records = Model.all(:limit => 3)
# new way
records = Model.limit(3).all
# you can also take advantage of lazy evaluation
records = Model.limit(3)
# then in your view
records.each { ... }
When upgrading to Rails 3, simply drop the named scope definition.
Constants
Avoid the usage of the following constants in favour of the corresponding Rails.x methods, already available in Rails 2.x.
RAILS_ROOT in favour of Rails.root,
RAILS_ENV in favour of Rails.env, and
RAILS_DEFAULT_LOGGER in favour of Rails.logger.
Unobtrusive Javascript
Avoid heavy JavaScript helpers in favour of unobtrusive JavaScript.
Gem dependencies
Keep your environment.rb as clean as possible in order to make easier the migration to Bundler. You can also anticipate the migration using Bundler today without Rails 3.
The release notes are the most important thing to keep an eye on. Other than that Jeremy McAnally has some neat blog posts about the whole Rails 3 thing (and has just released a gem to help you with the migration).
I'd say, read the rails release notes and see for yourself what seems the more surprising to you. A lot of stuff changed so reading this is definitively very important.