It doesn’t look like the Rails API exposes methods to do this generically. You could try accessing the underlying connection and using it’s methods, e.g. for MySQL: st = ActiveRecord::Base.connection.raw_connection.prepare(“update table set f1=? where f2=? and f3=?”) st.execute(f1, f2, f3) st.close I’m not sure if there are other ramifications to doing this (connections left open, … Read more
You can use validates_presence_of http://apidock.com/rails/ActiveModel/Validations/ClassMethods/validates_presence_of class A < ActiveRecord::Base has_many :bs validates_presence_of :bs end or just validates http://apidock.com/rails/ActiveModel/Validations/ClassMethods/validates class A < ActiveRecord::Base has_many :bs validates :bs, :presence => true end But there is a bug with it if you will use accepts_nested_attributes_for with :allow_destroy => true: Nested models and parent validation. In this topic you … Read more
You could try setting the ActiveRecord logger to stdout in your test somewhere. If you’re using rspec, maybe in the spec helper? ActiveRecord::Base.logger = Logger.new(STDOUT)
The ability to chain or clause along with where clause in ActiveRecord query will be available in Rails 5. See the related discussion and the pull request. So, you will be able to do the following things in Rails 5: To get a post with id 1 or 2: Post.where(‘id = 1’).or(Post.where(‘id = 2’)) Some … Read more
I was looking to use this for an after_save callback. A simpler solution is to use id_changed? (since it won’t change on update) or even created_at_changed? if timestamp columns are present. Update: As @mitsy points out, if this check is needed outside of callbacks then use id_previously_changed?. See docs.
There is a known issue with Rails 3.1.1 that breaks this functionality. If you are having this problem first try upgrading, it’s been fixed in 3.1.2 You’re so close. The problem is you’re misusing the :source option. :source should points to the polymorphic belongs_to relationship. Then all you need to do is specify :source_type for … Read more
Rails 6 Rails 6 added an upsert and upsert_all methods that deliver this functionality. Model.upsert(column_name: value) [upsert] It does not instantiate any models nor does it trigger Active Record callbacks or validations. Rails 5, 4, and 3 Not if you are looking for an “upsert” (where the database executes an update or an insert statement … Read more
Just change the first line as follows : include ActionView::Helpers that will make it works. UPDATE: For Rails 3 use: ActionController::Base.helpers.sanitize(str) Credit goes to lornc’s answer
add_index :subscriptions, [:user_id, :content_id], unique: true
Yes, just do: Challenge.find_by_id(10) For Rails 4 and 5: Challenge.find_by(id: 10)