php MySQL mysql_num_rows();
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时间：2020-08-25 03:25:23 来源:igfitidea点击:
MySQL mysql_num_rows();
提问by wesslayneb
I am not sure as to why. But the code I have created below is not working. The variable: "$num_rows" is not even being set and has no value (not even 0). Anyone know as to why this issue is occurring?
我不知道为什么。但是我在下面创建的代码不起作用。变量："$num_rows" 甚至没有被设置并且没有值（甚至不是 0）。有谁知道为什么会出现这个问题？
$result2 = mysql_query("SELECT * FROM `mycity_vehicles` WHERE `id` = '$vehID'");
while($row2 = mysql_fetch_array($result2))
$num_rows = mysql_num_rows($result2);
{
if(empty($num_rows)) {
echo "empty";
}
else {
echo $num_rows;
}
采纳答案by John Conde
Your syntax is off.
您的语法已关闭。
while($row2 = mysql_fetch_array($result2))
$num_rows = mysql_num_rows($result2);
{
should probably be
应该是
$num_rows = mysql_num_rows($result2);
while($row2 = mysql_fetch_array($result2))
{
回答by Orel Eraki
You did it the wrong order.
你做错了顺序。
$result2 = mysql_query("SELECT * FROM `mycity_vehicles` WHERE `id` = '$vehID'");
$num_rows = mysql_num_rows($result2);
while($row2 = mysql_fetch_array($result2)) {
if(empty($num_rows)) {
echo "empty";
}
else {
echo $num_rows;
}
