以下为一个简单登录系统的代码,本人找了很长时间的问题就是不知道出在哪里,数据库里有正确的数据,输入正确的帐号和密码就是出现错误。错误显示:Warning: mysql_num_rows(): supplied argument is not a valid MySQL result resource in C:\wamp\www\login\login.php on line 9
User doesn't exist!
(数据库链接文件没有问题,问题应该就在此页)
-----------------------------------------------------------------------------
以下是代码:
<?php
session_start();
include_once("conn.php");
$username = $_POST['username'];
$password = $_POST['password'];if($username&&$password){
$sql = mysql_query("select * from message where username='$username'");
$numrows = mysql_num_rows($sql);
if($numrows!=0){
while($row = mysql_fetch_assoc($sql)){
$dbusername = $row['username'];
$dbpassword = $row['password'];
}
if($username == $dbusername&&$password == $dbpassword){
echo "Login successfully! <a href='VIP.php'>Click here to the VIP area!</a>";
$_SESSION['username'] = $username;
} else {
echo "Incorrect password!";
}
} else
die("User doesn't exist!");
} else
die("Please write username and password!");?>
希望高手赐教,小弟在此先谢过了
User doesn't exist!
(数据库链接文件没有问题,问题应该就在此页)
-----------------------------------------------------------------------------
以下是代码:
<?php
session_start();
include_once("conn.php");
$username = $_POST['username'];
$password = $_POST['password'];if($username&&$password){
$sql = mysql_query("select * from message where username='$username'");
$numrows = mysql_num_rows($sql);
if($numrows!=0){
while($row = mysql_fetch_assoc($sql)){
$dbusername = $row['username'];
$dbpassword = $row['password'];
}
if($username == $dbusername&&$password == $dbpassword){
echo "Login successfully! <a href='VIP.php'>Click here to the VIP area!</a>";
$_SESSION['username'] = $username;
} else {
echo "Incorrect password!";
}
} else
die("User doesn't exist!");
} else
die("Please write username and password!");?>
希望高手赐教,小弟在此先谢过了
conn.php 的内容
及 conn.php 和 当前文件是不是在同一目录 。
程序输出之后在mysql上检验一下.
应改成:
$sql = mysql_query("select * from message where username='{$username}'");注意我加的大括号
$result=mysql_query($sql);
if(!$result)
{
echo $sql;
}