In Ruby on Rails, what's the difference between create and create! and API docs doesn't have it?
ActiveRecord has create
and some people use create!
... 开发者_Go百科Is it that create!
can raise an exception while create
doesn't? I can't find create!
in
the current Rails API docs...
Yes, create!
will raise an exception on failure, create
just returns false. Documentation here:
http://api.rubyonrails.org/classes/ActiveRecord/Validations/ClassMethods.html#method-i-create-21
I have tested it in Rails 4.2.0
. In this version of Rails, it seems, #create!
works as said in the other answer, but not the #create
method.
#create
creates an object (or multiple objects) and saves it to the database, if validations pass. The resulting object is returned whether the object was saved successfully to the database or not.
Here is some try as per the documentation.
Arup-iMac:rails_app_test shreyas$ rails c
Loading development environment (Rails 4.2.0)
[1] pry(main)> show-models Person
Person
id: integer
name: string
created_at: datetime
updated_at: datetime
[2] pry(main)> Person.create!
(0.1ms) begin transaction
(0.1ms) rollback transaction
ActiveRecord::RecordInvalid: Validation failed: Name can't be blank, Name is too short (minimum is 3 characters)
from /Users/shreyas/.rvm/gems/ruby-2.1.5@rails_app_test/gems/activerecord-4.2.0/lib/active_record/validations.rb:79:in `raise_record_invalid'
[3] pry(main)> Person.create
(0.1ms) begin transaction
(0.0ms) rollback transaction
=> #<Person:0x007fdb4cc5b0a0 id: nil, name: nil, created_at: nil, updated_at: nil>
[4] pry(main)> Person.count
(0.2ms) SELECT COUNT(*) FROM "people"
=> 0
[5] pry(main)>
Yes. An exception is raised if the record is invalid.
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