php生成唯一id

function kuangke_get_uniqid($create_len = 10)
/*****
*作者:狂客
*QQ:214109721
*时间:2021-01-13 20:42:26
*功能:生成唯一id
*参数:create_len 唯一id长度
*****/
{
    $code="ABCDEFGHIGKLMNOPQRSTUVWXYZ0123456789";
    $codelen = strlen($code) - 1;
    $id = '';
    for($i = 0;$i < $create_len;$i++)
    {
        $type = mt_rand(0, 2);
        switch($type)
        {
            case 0:
                $chr = uniqid();
                $len = strlen($chr);
                $chr = substr($chr, mt_rand(0, $len - 1),1);
                if(is_numeric($chr))
                    $id .= $code[$chr];
                else
                    $id .= $chr;
                break;
            case 1:
                $timestamp = microtime();
                $temp = str_replace(array(' ', '.', '0'), '', $timestamp);
                $len = strlen($temp);
                $chr = substr($temp, mt_rand(0, $len - 1),1);
                $id .= $code[mt_rand(0, $chr)];
                break;
            default:
                $id .= $code[mt_rand(0, $codelen)];
                break;
        }
    }
    return strtoupper($id);
}