Inequal Opportunity

inequal_opportunity exists because this does not work in ActiveRecord:

Doctor.all(:joins => :patients, :conditions => {:patients => ['age > ?', 20]})

You will get an unknown column exception looking for ‘doctors`.`age`. Instead, you need to write:

Doctor.all(:joins => :pateints, :conditions => ['`patients`.`age` > ?', 20])

Putting the string table name in the query annoyed me. On top of that, I always wanted a way to eliminate strings from my named scopes and queries. So now with inequal_opportunity you can write:

Doctor.all(:joins => :patients, :conditions => {:patients => {:age => gt(20)}})

Not only is it prettier (hashed), but ActiveRecord will keep track of table names for you.

ActiveRecord looks for Array and Range types to decide whether to use ‘IN’ or ‘BETWEEN’ instead of the normal ‘=’ as the comparison operator when generating SQL. inequal_opportunity extends that pattern by wrapping the value in a series of ActiveRecord::Inequality::Base classes. Just wrap the value with one of the following helper functions:

gte()     =>      >= 
gt()      =>      >
lte()     =>      <=
le()      =>      <
ne()      =>      <>
ne(nil)   =>      IS NOT

and the appropriate SQL will be generated. This works in finds, as shown above, in counts:

People.count(:age => gt(20))

in named scopes:

class People < AR::B
  named_scope :underage, :conditions => {:age => lte(18)}
end

in default scopes:

class Feedback < AR::B
  default_scope :conditions => {:type => ne('spam')}
end

and pretty much everywhere else I’ve tested manually.

Test coverage is kind of sparse right now, and it’s only been tested on MySQL. But it has been rock solid in every situation I’ve thrown it in, so I figured the best way to improve it was to release the hounds (YOU).

Note that I am not completely satisfied with the way I alias ActiveRecord::Base.expand_range_bind_variables. It smells, but it works. Suggestions welcome.

License

inequal_opportunity is released under the MIT license.

Support

Just email me at ryan@angilly.com with questions, bugs, or patches.