Possible Duplicate:
mysql_num_rows(): supplied argument is not a valid MySQL result resource
假设我有一个名为 getbyUsername 的函数在名为 User 的类文件中:
public static function getbyUsername($username) {
$user = new User();
$query = sprintf('SELECT CLIENT_ID, EMAIL, PASSWORD' . 'FROM %sClients WHERE USERNAME = "%s"', DB_TBL_PREFIX, mysql_real_escape_string($username, $GLOBALS['DB']));
$result = mysql_query($query, $GLOBALS['DB']);
if(mysql_num_rows($result)) {
$row = mysql_fetch_assoc($result);
$user->client_id = $row['CLIENT_ID'];
$user->username = $username;
$user->password = $row['PASSWORD'];
}
mysql_free_result($result);
return $user;
}
我将使用此函数检查用户是否存在
$user = User::getbyUsername($_POST['username']);
if($user->userid) {
echo 'User Exist!';
} else {
echo 'User does not exist';
}
我从 PHP 中收到错误，但我不知道为什么:
mysql_num_rows(): supplied argument is not a valid MySQL result resource in...
mysql_free_result(): supplied argument is not a valid MySQL result resource in....
有人可以帮助我吗？
最佳答案
您的查询似乎失败，因此 mysql_query 返回 false，这不是有效的 MySQL 结果资源。字段表达式 PASSWORD 和 FROM 关键字之间似乎缺少空格:
'SELECT CLIENT_ID, EMAIL, PASSWORD FROM %sClients WHERE USERNAME = "%s"'
关于PHP 错误 : mysql_num_rows(): supplied argument is not a valid MySQL，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/6483884/