A check if two date or time ranges A and B overlap needs to cover a lot of cases:
Note: Consider not doing this. Use form models or vanilla methods instead. The :conditions option for Rails associations cannot take...
Sometimes it is useful to define a named scope by implementing a static method with the scope's name on...
So you added a new callback to your model that (e.g.) caches some data when it is saved. Now you...
How to write to the db 27,000 times in 24 seconds instead of 9 minutes.
If you want to find out whether a Class object is directly inheriting from another class, use superclass: ActiveRecord::RecordNotFound.super...
When a has_many association basically serves to store a list of associated strings (tags, categories, ...), it can be convenient...
Don't insert table rows in a Rails database migration. This will break tests that expect that database to be...
Occasionally some complex query must be processed on the database because building thousands of Ruby objects is impracticable.
Plugins (and gems) are typically tested using a complete sample rails application that lives in the spec folder of the...
You most likely never want to do this. But if you do: Model.update_all({:id => new_id}, {:id => old_id...
To only run the next two migrations: rake db:migrate STEP=2 To revert the previous two migrations:
Use this scope: class Stick named_scope :shuffled, lambda { last_record = last { :conditions => [ 'id >= ?', rand(last_record.id) ] } if last_record }
You can now add an :inverse_of option to has_one, has_many and belongs_to associations.... Without :inverse_of...
When using form_for you can give the form's target URL either as a string or an array:
If you previously used version 2.x of Thunderbird and upgraded to 3.x (for example through an Ubuntu release...
If you need to look at the list of methods that are called upon certain events (like before/after saving etc...
If you get an ActiveRecord::RecordNotSaved error, a method inside one of your model's callback chains (before_save etc...
Did you use the :select option in a find, and forgot to include foo?
If you want to see how long your database queries actually take, you need to disable MySQL's query cache...
You can use record.send(:update_without_callbacks) or record.send(:create_without_callbacks) This can be used as a...
For some reason you want to define a find condition in array form. And in that condition both column name...
Find conditions for scopes can be given either as an array (:conditions => ['state = ?', 'draft']) or a hash (:conditions => { 'state' => 'draft...
When using virtual attributes, the attached trait can be useful to automatically copy errors from one attribute to another.