CODEWITHSUNDEEP
ruby-on-railsruby
Aswath Krishnan
Aswath Krishnan

Reputation: 1181

What does create! mean in rails?

What does this do in Rails? 

create! do |user| 
  #initialise user 
end

I figured it creates a user objects and saves it to the database. How is it different from just saying user.new(...) and user.save()?

Upvotes: 14

Views: 25656

Answers (3)

Aditya Sanghi
Aditya Sanghi

Reputation: 13433

In a nutshell:

  • create! raises an exception while create returns the object (unsaved object if it does not pass validations).
  • save! raises an error while save returns true/false.
  • save does not take attributes, create does.

new does not save. new is similar to build in ActiveRecord context. create saves to the database and returns true or false depending on model validations. create! saves to the database but raises an exception if there are errors in model validations (or any other error).

Upvotes: 34

Tilo
Tilo

Reputation: 33732

create takes attributes , so using a block here is somewhat unusual. The code you mention is doing the initialization in a block that is passed to create! It is in principal the same as new followed by the initialization and then a save!

There are many variations save, save!, create, ceate!, update, update!, etc., there are also variations in terms of validations, and call-backs

For details please check the API: (it is discussed in the first link)

http://api.rubyonrails.org/classes/ActiveRecord/Base.html

http://apidock.com/rails/ActiveRecord/Base

http://m.onkey.org/active-record-query-interface

Upvotes: -2

Victor Deryagin
Victor Deryagin

Reputation: 12215

When failed to create record, create! throws an exception, new and then save (or just create without exclamation mark) exit silently.

Upvotes: 4

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