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Question

我无法获取MySQL列。使用用户名，密码，数据库，表格和列设置mysql中的所有内容。

Warning: mysql_num_rows() expects parameter 1 to be resource, boolean given 
in /Applications/XAMPP/xamppfiles/htdocs/socialhut/login.php on line 8

这是login.php的代码：

<?php
$username = $_POST['username'];
$password = $_POST['password'];

$conn = mysqli_connect("localhost","root","","data");
$sql = "SELECT * FROM userdata WHERE username='$username' and password='$password'";
$query = mysql_query($sql);
$result = mysql_num_rows($query);

if ($result==1){
session_register($username);
session_register($password);
header('location:members.php');
}else{
mysql_error();
}
?>

任何人都可以搞清楚吗？ 谢谢！

Answer 1

您在同一代码中混合mysqli和mysql次来电。你不能这样做。

试试这个：

$conn = mysqli_connect("localhost","root","","data");
$sql = "SELECT * FROM userdata WHERE username='$username' and password='$password'";
$query = mysqli_query($conn, $sql);
if ($query === false) {die(mysqli_error($conn));}
$result = mysqli_num_rows($query);