Echoing Gareth’s comments… your code will not work as written. It should be rewritten this way: def name=(name) write_attribute(:name, name.capitalize) end def name read_attribute(:name).downcase # No test for nil? end
If it is just avoiding the exception you are worried about, the “find_all_by..” family of functions works without throwing exceptions. Comment.find_all_by_id([2, 3, 5]) will work even if some of the ids don’t exist. This works in the user.comments.find_all_by_id(potentially_nonexistent_ids) case as well. Update: Rails 4 Comment.where(id: [2, 3, 5])
Rails 3+ Enter this line in the console: ActiveRecord::Base.logger = Logger.new(STDOUT) Rails 2 Enter this line in the console: ActiveRecord::Base.connection.instance_variable_set :@logger, Logger.new(STDOUT)
From within rails you can create a configuration object and obtain the necessary information from it: config = Rails.configuration.database_configuration host = config[Rails.env][“host”] database = config[Rails.env][“database”] username = config[Rails.env][“username”] password = config[Rails.env][“password”] See the documentation for Rails::Configuration for details. This just uses YAML::load to load the configuration from the database configuration file (database.yml) which you can … Read more
If you are using the Rails 4.x you can now generate migrations with references, like this: rails generate migration AddUserRefToProducts user:references like you can see on rails guides
You would do Person.where(‘name=? OR lastname=?’, ‘John’, ‘Smith’) Right now, there isn’t any other OR support by the new AR3 syntax (that is without using some 3rd party gem).
You can also delegate: class Company < ActiveRecord::Base has_many :employees has_many :dogs, :through => :employees end class Employee < ActiveRescord::Base belongs_to :company has_many :dogs end class Dog < ActiveRecord::Base belongs_to :employee delegate :company, :to => :employee, :allow_nil => true end
For Schema related stuff Model.column_names Model.columns_hash Model.columns For instance variables/attributes in an AR object object.attribute_names object.attribute_present? object.attributes For instance methods without inheritance from super class Model.instance_methods(false)
From the documentation, it seems like the :inverse_of option is a method for avoiding SQL queries, not generating them. It’s a hint to ActiveRecord to use already loaded data instead of fetching it again through a relationship. Their example: class Dungeon < ActiveRecord::Base has_many :traps, :inverse_of => :dungeon has_one :evil_wizard, :inverse_of => :dungeon end class … Read more
This is the Rails 3 way SomeModel.last(5) # last 5 records in ascending order SomeModel.last(5).reverse # last 5 records in descending order