Class: ActiveRecord::Base

Inherits:
Object
  • Object
show all
Defined in:
lib/roqua/core_ext/activerecord/uniq_find_or_create.rb

Class Method Summary collapse

Class Method Details

.uniq_find_or_create_by(attributes, &block) ⇒ Object

Use this method to find or create records that have uniqueness constraints enforced by the database. After calling the AR find_or_create_by method it queries the preexisting or created record by the attributes provided, thereby ensuring that a concurrently created record is returned when a AR RecordNotUnique error is raised. When no record can be found, because for instance validations fail on create, the created object containing the validation errors is returned instead.



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# File 'lib/roqua/core_ext/activerecord/uniq_find_or_create.rb', line 10

def self.uniq_find_or_create_by(attributes, &block)
  find_or_create_by(attributes, &block)
# When a real race condition occurs, activerecord has no clue about a uniqueness constraint
# being violated (this is exactly why validates :attribute, uniqueness: true does not work
# for these cases) and a plain Mysql2::Error exception is raised instead of
# ActiveRecord::RecordNotUnique
rescue Mysql2::Error => exception
  find_by(attributes) || raise(exception)
rescue ActiveRecord::RecordNotUnique => exception
  find_by(attributes) || raise(exception)
end

.uniq_find_or_create_by!(attributes, &block) ⇒ Object

Use this method if you want an exception to be raised when creating a new record fails due to some validation error other than uniqueness.



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# File 'lib/roqua/core_ext/activerecord/uniq_find_or_create.rb', line 24

def self.uniq_find_or_create_by!(attributes, &block)
  find_or_create_by!(attributes, &block)
# When a real race condition occurs, activerecord has no clue about a uniqueness constraint
# being violated (this is exactly why validates :attribute, uniqueness: true does not work
# for these cases) and a plain Mysql2::Error exception is raised instead of
# ActiveRecord::RecordNotUnique
rescue Mysql2::Error => exception
  find_by(attributes) || raise(exception)
rescue ActiveRecord::RecordNotUnique => exception
  find_by(attributes) || raise(exception)
rescue ActiveRecord::RecordInvalid => exception
  find_by(attributes) || raise(exception)
end