title: mysql using BTREE
body: <p>How to solve this problem?<br>
  My table structure:</p>
  
  <pre><code>CREATE TABLE IF NOT EXISTS `tbl_foster_network` (
    `network_id` int(11) NOT NULL COMMENT 'Network ID',
    `network_name` varchar(64) NOT NULL COMMENT 'Network Name',
    `network_domain` varchar(45) NOT NULL COMMENT 'Network Domain',
    `created_when` datetime NOT NULL COMMENT 'Created When',
    `last_modified_by` int(11) NOT NULL COMMENT 'Last Modified By',
    `last_modified_when` datetime NOT NULL COMMENT 'Last Modified When',
    PRIMARY KEY (`network_id`),
    UNIQUE KEY `network_domain` (`network_id`,`network_name`,`network_domain`) USING BTREE
  ) ENGINE=InnoDB DEFAULT CHARSET=latin1 COMMENT='Network';
  </code></pre>
  
  <p>Error</p>
  
  <pre><code>1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'USING BTREE
  ) ENGINE=InnoDB DEFAULT CHARSET=latin1 COMMENT='Network'' at line 16 
  </code></pre>