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php中关于sql拼接时标点符号出现的有关问题

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Jun 13, 2016 am 11:56 AM

fromidnbspparenttable

php中关于sql拼接时标点符号出现的问题
初学php,遇到了个奇怪的问题，让大侠们见笑了，拼接语句如下：

 $sql = 'select cat_id,cat_name,parent_id from ' . $this->table . ' where parent_id=' . $id;//能通过，正解<br /><br />  $sql = 'select cat_id,cat_name,parent_id from' . $this->table . 'where parent_id=' . $id;

为啥符号的空位不同，拼接的结果会有差异，不解中，求解答？
------解决方案--------------------
你把两句输出之后对比下就知道了。
第一句.... from table where...
第一句.... fromtablewhere...

第二句中from 、table和where连在一起了，还能正确吗？

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