Rails: Update model attribute without invoking callbacks

Question

I have a User model that has a :credits attribute. I want a simple button that will add 5 to the user's credits, through a route called "add" so that /users/3/add would add 5 to the credits of user id = 3.

def add
    @user = User.find(params[:id])
    @user.credits += 5
    redirect_to root_path
end

That is the relevant part of my controller. The problem is, I dont want to call @user.save because I have a before_save callback that re-encrypts the user's password based on the current UTC time. I just want to simply add 5 to the attribute and avoid the callback, I never thought such a simple thing could be so hard.

EDIT:

I changed the callback to :before_create, here is my new controller code (relevant part):

  def add
    @user = User.find(params[:id])
    @user.add_credits(5)
    @user.save
    flash[:success] = "Credits added!"
    redirect_to root_path
  end

and here is my code in the model:

 def add_credits(num)
    self.credits = num
 end

EDIT 2:

Ok it was a validation problem that made the changes in "EDIT" not work, but I'd still love an answer to the original question of updating without callbacks!

Solution 1

Rails 3.1 introduced update_column, which is the same as update_attribute, but without triggering validations or callbacks:

http://apidock.com/rails/ActiveRecord/Persistence/update_column

Solution 2

As a general answer, in Rails 4 this is a simple way to update attributes without triggering callbacks:

@user.update_column :credits, 5

If you need to update multiple attributes without triggering callbacks:

@user.update_columns credits: 5, bankrupt: false  

There are other options here in the Rails Guides if you prefer, but I found this way to be the easiest.

Solution 3

To update multiple attributes without callbacks you can use update_all in your model as so:

self.class.update_all({name: value, name: value}, self.class.primary_key => id)

If you really want you can even try even a update_columns method and mixin this to your active record base class.

To update one attribute you can use update_column. In addition there is some specific methods that can found in the rails guides http://guides.rubyonrails.org/active_record_callbacks.html#skipping-callbacks

Solution 4

For mongoid, I ended up using http://mongoid.org/en/mongoid/docs/persistence.html Specifically, you can use:

person.set(name:"Robert Pulson")

and no callback will be issued. So cool.

Solution 5

I think you should use the method update_counters in this case. Use it like this in your controller action:

def add
  User.update_counters params[:id], :credits => 5
  redirect_to root_path
end

View more solutions

Comments

[Dave Newton]

I provided a link with a list of the methods that don't trigger callbacks, and both Finbarr and I suggested using a conditional callback--what additional solutions are you looking for?

[Sam Stern]

Ok I changed it to "after_create" but it still won't work! See my edit for my new code, I can't get credits to change.

[Dave Newton]

@hatboysam Well, it does something different--before you were adding, now you're setting. Use save! to see if there's an exception (and/or check the logs, and/or remove the backtrace silencers).

[Sam Stern]

I would love to use this but I can't upgrade to Rails 3.1 cleanly, or at least I don't know how.

[cvshepherd]

Which Rails version are you running at the moment?

[Jude Calimbas]

its person.set(:name, "Robert Pulson")

[Richard H Fung]

user.update_column credits:5 does not work. It should be user.update_column 'credits', 5

[Matt]

I'm using Rails 4.2 and this definitely works for me. This line generates the following query: UPDATE "users" SET "credits" = $1, "updated_at" = $2 WHERE "users"."id" = $3 [["credits", 5], ["updated_at", "2017-04-01 21:34:52.746626"], ["id", 1]]

[rept]

@JudeCalimbas no it's not, ArgumentError: wrong number of arguments (given 2, expected 1)

[Joshua Pinter]

When using update_column, you can't pass it an Object like credits: 5. You have to pass two parameters, the first being the column name and the second being the value to update it to. So you can do update_column :credits, 5, which would generally be preferred over using a String for the column name.