From: http://api.rubyonrails.org/classes/ActiveRecord/Associations/ClassMethods.html :touch If true, the associated object will be touched (the updated_at/on attributes set to now) when this record is either saved or destroyed. If you specify a symbol, that attribute will be updated with the current time in addition to the updated_at/on attribute. belongs_to :company, :touch => true belongs_to :company, :touch => :employees_last_updated_at
Looks like you don’t need nested joins here. Try to use something like Event.joins(:store).where(stores: {retailer_id: 2}) Nested join should also work using stores Event.joins(:store => :retailer).where(stores: {retailer: {id: 2}})
Rails 2 If you are still on rails 2 you will need to use: Client.select(‘distinct(name)’) Rails 3 If you are on Rails 3 you will need to use: Client.select(:name).uniq If you look at the equivalent section of the rails 3 guide you can see the difference between the two versions. Rails 4+ The .distinct option … Read more
All migrations are wrapped in transaction by default so that they can be rolled back when they are failed. You need to use disable_ddl_transaction when you want to do something that can not excute inside a transaction. You can check Transactional Migrations section of Migration document for example.
If you want to continue using order by random() then just declare it safe by wrapping it in Arel.sql like the deprecation warning suggests: Model.order(Arel.sql(‘random()’)).first # PostgreSQL Model.order(Arel.sql(‘rand()’)).first # MySQL There are lots of ways of selecting a random row and they all have advantages and disadvantages but there are times when you absolutely must … Read more
Another approach is using ActiveRecord::QueryCache::ClassMethods#uncached Model.uncached do # your code end
Like this? ⚡️ irb 2.2.2 :001 > [1,2,3] + [4,5,6] => [1, 2, 3, 4, 5, 6] But you don’t have 2 arrays. You could do something like: @movie = Movie.first() @options = Movie.order(“RANDOM()”).first(3).to_a << @movie
Try something like: Person.select(“id, age”).group(:id, :age).having(“count(id) > 1”).order(“age desc”)
You should look at the problem from a different perspective. Testing whether a function uses a transaction is useless from a behavioral viewpoint. It does not give you any information on whether the function BEHAVES as expected. What you should test is the behavior, i.e. expected outcome is correct. For clarity, lets say you execute … Read more
Here is the correct syntax to iterate over all User : User.all.each do |user| #the code here is called once for each user # user is accessible by ‘user’ variable # WARNING: User.all performs poorly with large datasets end To improve performance and decrease load, use User.find_each (see doc) instead of User.all. Note that using … Read more