Flowdock
method

first_or_create

Importance_3
v3.2.3 - Show latest stable - 2 notes - Class: ActiveRecord::Relation
first_or_create(attributes = nil, options = {}, &block) public

Tries to load the first record; if it fails, then create is called with the same arguments as this method.

Expects arguments in the same format as Base.create.

Examples

# Find the first user named Penélope or create a new one.
User.where(:first_name => 'Penélope').first_or_create
# => <User id: 1, first_name: 'Penélope', last_name: nil>

# Find the first user named Penélope or create a new one.
# We already have one so the existing record will be returned.
User.where(:first_name => 'Penélope').first_or_create
# => <User id: 1, first_name: 'Penélope', last_name: nil>

# Find the first user named Scarlett or create a new one with a particular last name.
User.where(:first_name => 'Scarlett').first_or_create(:last_name => 'Johansson')
# => <User id: 2, first_name: 'Scarlett', last_name: 'Johansson'>

# Find the first user named Scarlett or create a new one with a different last name.
# We already have one so the existing record will be returned.
User.where(:first_name => 'Scarlett').first_or_create do |user|
  user.last_name = "O'Hara"
end
# => <User id: 2, first_name: 'Scarlett', last_name: 'Johansson'>
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November 6, 2014
6 thanks

Find the First Instance in the Table. If None Exists, Create One.

Specify the data you’re looking for. If it exists in the table, the first instance will be returned. If not, then create is called.

If a block is provided, that block will be executed only if a new instance is being created. The block is NOT executed on an existing record.

Code example

MyStat.where(name: statistic_name).first_or_create do |statistic|
  statistic.value = calculate_percentage
  statistic.statistic_type = "percentage"
end
January 22, 2016
0 thanks

Creates record by given attributes only if table is empty

This method first searches the table for ANY FIRST RECORD, not the one matching given attributes. If no record is found at all, it creates one using the specified attributes. This might be misunderstood in many cases.