rendered paste body>> params['UserAttr']['3']
=> {"op"=>"+=", "type"=>"check", "value"=>"cd", "user_id"=>1, "attribute_id"=>"42"}
>> attribute = UserAttr.new(params['UserAttr']['3'])
ActiveRecord::AssociationTypeMismatch: Attribute expected, got Array
+--------------+-----------------------+------+-----+---------------------+----------------+
| Field | Type | Null | Key | Default | Extra |
+--------------+-----------------------+------+-----+---------------------+----------------+
| id | int(11) | NO | PRI | NULL | auto_increment |
| user_id | int(11) | NO | MUL | NULL | |
| attribute_id | int(11) | NO | MUL | NULL | |
| op | varchar(2) | NO | | NULL | |
| value | varchar(253) | NO | | NULL | |
| created_on | timestamp | YES | | 0000-00-00 00:00:00 | |
| updated_on | timestamp | YES | | CURRENT_TIMESTAMP | |
| type | enum('reply','check') | NO | | NULL | |
+--------------+-----------------------+------+-----+---------------------+----------------+