PHP的BUG? preg_replace后导致查询语句失效问题

[jimx92]

以下PHP代码里的mysql查询为何得不到结果?
$a = 'Gifts & Party Supplies';
$a = strval(preg_replace("/[[:punct:]]/","",strtolower($a)));// 把&等标点符号去掉,并转为小写 $a='gifts party supplies';
$master_category_id_sql = "select categories_id from categories_description where lower(categories_name)='". $a ."' ";
echo $master_category_id_sql;//查询语句是: select categories_id from categories_description where lower(categories_name)='gifts party supplies'
$master_category_id_q = mysql_query($master_category_id_sql);
$master_category_id_r = mysql_fetch_array($master_category_id_q);
$master_category_id = $master_category_id_r['categories_id'];//产品目录ID
var_dump($master_category_id);//null
我发现php代码中多了那一句: preg_replace("/[[:punct:]]/","",strtolower($a)) 后, 后面的sql查询就得不到结果.
我直接把select categories_id from categories_description where lower(categories_name)='gifts party supplies'这句放到mysql里查询是可以得到结果的.
或者我把这行代码 $master_category_id_sql = "select categories_id from categories_description where lower(categories_name)='". $a ."' "; 里的变量$a去掉, 写成$master_category_id_sql = "select categories_id from categories_description where lower(categories_name)='gifts party supplies' "; 也是可以得到结果的.

问题就出在preg_replace("/[[:punct:]]/","",strtolower($a))这行.
百思不得其解. 麻烦大家解析一下.

[xuzuning]

$a = 'Gifts & Party Supplies';
echo $a = strval(preg_replace("/[[:punct:]]/","",strtolower($a)));// 把&等标点符号去掉,

得到的是 gifts party supplies 注意：gifts 后面有两个空格
而你测试成功的是 gifts party supplies 注意：gifts 后面只有一个空格

这就不难理解了吧

[焦sir]

先想想是不自己的bug

[码无边]

输出语句看看。

[jaksmine]

[Quote=引用 1 楼 xuzuning 的回复:]
$a = 'Gifts & Party Supplies';
echo $a = strval(preg_replace("/[[:punct:]]/","",strtolower($a)));// 把&等标点符号去掉,

得到的是 gifts party supplies 注意：gifts 后面有两个空格
而你测试成功的是 gifts party supplies 注意：……
[/Quote]

不是这个问题，楼主是(preg_replace("/[[:punct:]]/","",strtolower($a)))，把标点换成"",又不是
" ",怎么会多一个空格，而且我输出了两个sql，的确是一样的
$a = 'Gifts Party Supplies';
$a = strval(preg_replace("/[[:punct:]]/","",strtolower($a)));// 把&等标点符号去掉,并转为小写 $a='gifts party supplies';
/*echo $a;*/
$master_category_id_sql1 = "select categories_id from categories_description where lower(categories_name)='". $a ."' ";
echo $master_category_id_sql1.'<br>';

$master_category_id_sql2 = "select categories_id from categories_description where lower(categories_name)='gifts party supplies' ";
echo $master_category_id_sql2.'<br>';

两个sql一摸一样。。。。真是太奇怪了。

帮楼主顶帖，我也不知道是怎么回事，求高手指教。。。。