Method: ActiveRecord::CounterCache::ClassMethods#reset_counters

Defined in:
lib/active_record/counter_cache.rb

#reset_counters(id, *counters) ⇒ Object

Resets one or more counter caches to their correct value using an SQL count query. This is useful when adding new counter caches, or if the counter has been corrupted or modified directly by SQL.

Parameters

  • id - The id of the object you wish to reset a counter on.

  • counters - One or more association counters to reset

Examples

# For Post with id #1 records reset the comments_count
Post.reset_counters(1, :comments)



20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
 
# File 'lib/active_record/counter_cache.rb', line 20

def reset_counters(id, *counters)
  object = find(id)
  counters.each do |association|
    has_many_association = reflect_on_association(association.to_sym)
    raise ArgumentError, "'#{self.name}' has no association called '#{association}'" unless has_many_association

    if has_many_association.is_a? ActiveRecord::Reflection::ThroughReflection
      has_many_association = has_many_association.through_reflection
    end

    foreign_key  = has_many_association.foreign_key.to_s
    child_class  = has_many_association.klass
    belongs_to   = child_class.reflect_on_all_associations(:belongs_to)
    reflection   = belongs_to.find { |e| e.foreign_key.to_s == foreign_key && e.options[:counter_cache].present? }
    counter_name = reflection.counter_cache_column

    stmt = unscoped.where(arel_table[primary_key].eq(object.id)).arel.compile_update({
      arel_table[counter_name] => object.send(association).count
    })
    connection.update stmt
  end
  return true
end