[英]Warning: mysql_num_rows(): supplied argument is not a valid
Hi i'm receiving the error below, i've double checked everything and don't know why its being displayed. 嗨,我收到以下错误,我已经仔细检查了所有内容,不知道为什么会显示它。 Warning: mysql_num_rows(): supplied argument is not a valid MySQL result resource in /home/namebob/public_html/site_reg/statlookup.php on line 6
警告:mysql_num_rows():提供的参数不是第6行/home/namebob/public_html/site_reg/statlookup.php中的有效MySQL结果资源
<?php
include_once('common.php');
$cid = $_REQUEST['cid'];
$_elmID = $_REQUEST['elmID'];
$scan = mysql_query("SELECT `id`, `state` FROM `mast_state` WHERE `countryid` = $cid");
if(mysql_num_rows($scan)>0)
{
...
It's worth trying var_dump($scan)
, if you get something like null / false, that means the query fails. 值得尝试
var_dump($scan)
,如果得到类似null / false的信息,则意味着查询失败。 If that's the case, try echo mysql_error()
to check for any sql error (missing table etc) 如果是这种情况,请尝试
echo mysql_error()
以检查是否存在任何SQL错误(缺少表等)
Most probably your query is failing. 您的查询很可能失败。 Try:
尝试:
if($scan) {
if(mysql_num_rows($scan) > 0) {
//...
}
} else {
trigger_error(mysql_error());
};
$scan = mysql_query("SELECT `id`, `state` FROM `mast_state` WHERE `countryid` = $cid");
$stock_num = '';
if($scan )
{
while($row=mysql_fetch_object($scan))
{
if($row->state)
$state = $row->state;
}
}
$scan = mysql_query("SELECT `id`, `state` FROM `mast_state` WHERE `countryid` = '".mysql_real_escape_string($cid)."'");
But really, use PDO. 但实际上,使用PDO。
$stm = $db->prepare("SELECT `id`, `state` FROM `mast_state` WHERE `countryid` = ?"); if( $stm && $stm->execute(array($cid)) ) { while( $data = $stm->fetch(PDO::FETCH_ASSOC) ) { } }
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