def validate_each(record, attribute, value)
finder_class = find_finder_class_for(record)
table = finder_class.unscoped
table_name = record.class.quoted_table_name
if value && record.class.serialized_attributes.key?(attribute.to_s)
value = YAML.dump value
end
sql, params = mount_sql_and_params(finder_class, table_name, attribute, value)
relation = table.where(sql, *params)
Array.wrap(options[:scope]).each do |scope_item|
scope_value = record.send(scope_item)
relation = relation.where(scope_item => scope_value)
end
unless record.new_record?
relation = relation.where("#{record.class.quoted_table_name}.#{record.class.primary_key} <> ?", record.send(:id))
end
if relation.exists?
record.errors.add(attribute, :taken, options.except(:case_sensitive, :scope).merge(:value => value))
end
end