我有一个问题，我不能用逗号分隔数组，如果我放入内爆，它只显示数据库中的第一个数字，而不是第二个数字，我需要在数据库500756中插入

global $wpdb;  $arg=array(500,756);

$var = implode(",", $arg);   --> return in db 500 ->I can not separate by commas, num 500 is only show in db 
$var = implode($arg);        --> if i put this instead of the other return in db shows 500756

     $wpdb->insert(\'number\',array( 
          \'num\' => $var,   
        ));  

CREATE TABLE `number` (
  `id` int(255) NOT NULL,
  `num` varchar(255) NOT NULL,
) ENGINE=MyISAM DEFAULT CHARSET=latin1;


ALTER TABLE `number`
  ADD PRIMARY KEY (`id`);

ALTER TABLE `number`
  MODIFY `id` int(255) NOT NULL AUTO_INCREMENT, AUTO_INCREMENT=39;