Currently I am running something similar to this command: Person.sum(:cholesterol, :group => :age) which seems to work great when I have a small number of records. However when I attempt to call
I have a table with columns \'id\', \'resource_id\', \'read_time\', \'value\' where \'value\' is a float
Let\'s say I have models that look like this: class Foo < ActiveRecord::Base has_man开发者_Go百科y :bars, :through => :cakes
I have heard over and over that you should add indexes to any foreign key you will be doing joins on.I have also heard you should have indexes for fields you will do queries on.Does anyone have a fair
I am running into a problem with to_json not rendering my virtual attributes class Location < ActiveRecord::Base
Why does the ruby on rails migration syntax look like this: create_table :my_table do |t| t.integer :col
Let\'s say I have a Course in which Students can enroll via a Membership (e.g. a has_and_belongs_to_many relationsip of Courses and Students).Some memberships are for students who are just observing t
I am aware of ActiveRecord::Dirty and the related methods, but I don\'t see a means by which I can subscribe to an attribute changed event.Something like:
I was wondering if it was possible to use the find method to order the results based on a class\'s has_many relationship with another class. e.g.
How do rails association methods work? Lets consider this example class User < ActiveRecord::Base has_many :articles
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