Description:
------------
mysqli seems to return the length of the column inside the undocumented "length" property, whereas max_length seems to be 0 all the time ..

Reproduce code:
---------------
CREATE TABLE `users` (
  `user_name` char(12) default NULL,
  `user_password` text,
  `subscribed` tinyint(4) default NULL,
  `user_id` int(11) NOT NULL default '0',
  `quota` decimal(18,2) default NULL,
  `weight` double default NULL,
  `access_date` date default NULL,
  `access_time` time default NULL,
  `approved` datetime default NULL,
  UNIQUE KEY `users_id_index_idx` (`user_id`)
);

Actual result:
--------------
name:    user_name
max_length: 0
length: 12
type:    254

name:    user_password
max_length: 0
length: 65535
type:    252

name:    subscribed
max_length: 0
length: 4
type:    1

name:    user_id
max_length: 0
length: 11
type:    3

name:    quota
max_length: 0
length: 20
type:    246

name:    weight
max_length: 0
length: 22
type:    5

name:    access_date
max_length: 0
length: 10
type:    10

name:    access_time
max_length: 0
length: 8
type:    11

name:    approved
max_length: 0
length: 19
type:    12