String access operator []

mysql> CREATE TABLE `test` (

  `id` int(11) NOT NULL AUTO_INCREMENT,

  `data` varchar(100) NOT NULL,

  PRIMARY KEY (`id`)

) ENGINE=InnoDB;

mysql> INSERT INTO `test` (`id`,`data`) VALUES(0,'');

mysql> UPDATE `test` SET `data`[5] = 'xxx';

mysql> SELECT * FROM `test` WHERE `id`=0;

+-----+----------------------------+

| sid | data                       |

+-----+----------------------------+

|   0 | '     xxx'

+-----+----------------------------+

mysql> UPDATE `test` SET `data`[3] = 'aaa';

mysql> SELECT * FROM `test` WHERE `id`=0;

+-----+----------------------------+

| sid | data                       |

+-----+----------------------------+

|   0 | '   aaaxx'

+-----+----------------------------+

mysql> UPDATE `test` SET `data`[3:1] = 'bbbbbb';

mysql> SELECT * FROM `test` WHERE `id`=0;

+-----+----------------------------+

| sid | data                       |

+-----+----------------------------+

|   0 | '   baaxx'

+-----+----------------------------+

mysql> SELECT `data`[4:3] FROM `test` WHERE `id`=0;

+----------------------------+

| data                       |

+----------------------------+

| 'aax'

+----------------------------+