php – 优惠券系统的随机码生成器

这对于随机优惠券代码生成器来说是否足够好?在制作新代码时,我应该检查并查看代码是否已被使用?这会重复的几率是多少?

$coupon_code = substr(base_convert(sha1(uniqid(mt_rand())), 16, 36), 0, 7);

编辑 – 这是我的实际代码:

$coupon_code = substr(base_convert(sha1(uniqid(mt_rand())), 16, 36), 0, 7);
$numrows = mysql_num_rows(mysql_query("SELECT id FROM generatedcoupons WHERE coupon_code='$coupon_code' LIMIT 1"));
if($numrows>0){
     $coupon_code =  substr(base_convert(sha1(uniqid(rand())), 16, 36), 0, 7);
     $numrows = mysql_num_rows(mysql_query("SELECT id FROM generatedcoupons WHERE coupon_code='$coupon_code' LIMIT 1"));
     if($numrows>0)
          //error, show link to retry
}

最佳答案 这是一个优惠券系统,不仅可以保证唯一的代码,而且在查找时非常有效:

// assuming MySQL table with (id, code, effect)
mysql_query( "insert into `coupons` set `effect`='".$effect."'");
// "effect" will be some keyword to identify what the coupon does
$id = mysql_insert_id();
$code = $id."F";
$codelen = 32; // change as needed
for( $i=strlen($code); $i<$codelen; $i++) {
    $code .= dechex(rand(0,15));
}
mysql_query( "update `coupons` set `code`='".$code."' where `id`=".$id);

// now, when you are given a code to redeem, say $_POST['code']
list($code,$effect) = mysql_fetch_row( mysql_query( "select `code`, `effect` from `coupons` where `id`='".((int) $_POST['code'])."'"));
if( $code != $_POST['code']) die("Code not valid");
else {
    // do something based on $effect
}

如您所见,它从AUTO_INCREMENT获取ID,附加F,然后使用随机十六进制字符填充.您可以根据需要制作$codelen,但32应该足够(即使在第100万张优惠券之后也可以提供大约16 ** 26种组合).

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