method
find_each
rails latest stable - Class:
ActiveRecord::Batches::ClassMethods
find_each(options = {})public
Yields each record that was found by the find options. The find is performed by find_in_batches with a batch size of 1000 (or as specified by the :batch_size option).
Example:
Person.find_each(:conditions => "age > 21") do |person| person.party_all_night! end
Note: This method is only intended to use for batch processing of large amounts of records that wouldn’t fit in memory all at once. If you just need to loop over less than 1000 records, it’s probably better just to use the regular find methods.
3Notes
Will discard any order option
order_by(:created_at).find_each == FAIL!!!
class ActiveRecord::Base
# normal find_each does not use given order but uses id asc
def self.find_each_with_order(options={})
raise "offset is not yet supported" if options[:offset]
page = 1
limit = options[:limit] || 1000
loop do
offset = (page-1) * limit
batch = find(:all, options.merge(:limit=>limit, :offset=>offset))
page += 1
batch.each{|x| yield x }
break if batch.size < limit
end
end
end
You can't use the :limit option either
Person.find_each(:limit => 10000)...
Will result in:
RuntimeError: You can't specify a limit, it's forced to be the batch_size
Will discard :select
==== Only does SELECT model.id FROM models_table
regardless of select options
