php CI框架 使用PDO 的连接配置

$db['default'] = array(
    'dsn' => 'mysql:dbname=hejun;host=192.168.137.127',
    //'hostname' => '',
    
    'username' => 'mysqluser',
    'password' => 'whj123',
    //'database' => 'hejun',

    'dbdriver' => 'pdo',     //改为pdo
    'dbprefix' => '',
    'pconnect' => FALSE,
    'db_debug' => (ENVIRONMENT !== 'production'),
    'cache_on' => FALSE,
    'cachedir' => '',
    'char_set' => 'utf8',
    'dbcollat' => 'utf8_general_ci',
    'swap_pre' => '',
    'encrypt' => FALSE,
    'compress' => FALSE,
    'stricton' => FALSE,
    'failover' => array(),
    'save_queries' => TRUE
);