num_row errors

[Alidad]

Hi, i need help to solve this case, I'm trying to create login forms, and i got errors it said
"mysql_num_rows() expects parameter 1 to be resource, boolean given in line 18.

i can't figure out what this mean and how to solve it. here is code, please see line 18 in bold where it said

$count=mysql_num_rows($result);

ob_start(); 
// Connect to server and select databse.
include ('conn.php');
// Define $myusername and $mypassword
$myusername=$_POST['username'];
$mypassword=$_POST['password'];
// To protect MySQL injection (more detail about MySQL injection)
$myusername = stripslashes($myusername);
$mypassword = stripslashes($mypassword);
$myusername = mysql_real_escape_string($myusername);
$mypassword = mysql_real_escape_string($mypassword);
$sql="SELECT * FROM `members` WHERE username='$myusername' and password='$mypassword'";
//echo  $sql;

$result=mysql_query($sql);
// Mysql_num_row is counting table row
[B]$count=mysql_num_rows($result);[/B]

// If result matched $myusername and $mypassword, table row must be 1 row

if($count==1){
// Register $myusername, $mypassword and redirect to file "login_success.php"
echo $myusername;
$_SESSION['myusername'] = $myusername;
//header("location:login_success.php");
}
else {
echo "";
//header("location:index.php?a='failed'");
}
ob_flush();
?>

does anyone can help me please thanks.

AM

[bradgrafelman]

It means exactly what it says: the function [man]mysql_num_rows/man expects the first parameter to be of the [man]resource[/man] type, but instead you passed it a [man]boolean[/man]. Read the manual page for the function that gave you that boolean rather than the resource and you'll probably find that an error has occurred. For example, you never check to see if [man]mysql_query/man was successful and, if it wasn't, output the MySQL error message retrievable via [man]mysql_error/man to aid in debugging.

Then again, note the 'Suggested Alertnatives' box that appears at the top of the manual pages for all of the mysql_*() functions; the entire [man]mysql[/man] extension is outdated and has been deprecated in favor of newer extensions such as [man]MySQLi[/man] or [man]PDO[/man].

EDIT: Also note that you should never have to use [man]stripslashes/man on incoming data.

[Alidad]

sorry are you refer to change like this

from:

$sql="SELECT * FROM `tbl_real-regs` WHERE username='$myusername' and password='$mypassword'";
//echo  $sql;

$result=mysql_query($sql);
// Mysql_num_row is counting table row
$count=mysql_num_rows($result);


to:

$query="SELECT * FROM `tbl_real-regs` WHERE username='$myusername' and password='$mypassword'";
//echo  $sql;

$result=mysql_query($query);
// Mysql_num_row is counting table row
$count=mysql_num_rows($result);

only change from $sql to $query! if this case, i'm still getting same errors.

AM

[Alidad]

i changed that code and i'm still getting errors but this time is new errors..

please see code

<?php
ob_start();
// Connect to server and select databse.
include ('conn.php');
// Define $myusername and $mypassword
$myusername=$POST['username'];
$mypassword=$POST['password'];
// To protect MySQL injection (more detail about MySQL injection)
$myusername = stripslashes($myusername);
$mypassword = stripslashes($mypassword);
$myusername = mysql_real_escape_string($myusername);
$mypassword = mysql_real_escape_string($mypassword);

$sql="SELECT * FROM members WHERE username='$myusername' and password='$mypassword'";
if(!$result) die ('Unable to run query:'.mysql_error());

$count=mysql_num_rows($result);

// If result matched $myusername and $mypassword, table row must be 1 row

if($count==1){
// Register $myusername, $mypassword and redirect to file "login_success.php"
echo $myusername;
$_SESSION['myusername'] = $myusername;
//header("location:login_success.php");
}
else {
echo "Wrong Email or Password";
//header("location:index.php?a='failed'");
}
ob_flush();
?>

and the result i got line in bold "unable to run query...

what did i missed!

AM

[sneakyimp]

Alidad, you need to take a moment and carefully read bradgrafelman's post. You are just stabbing in the dark.

[DeadlySin3]

So - are you just trying to count the number or rows in your results? What I do is something like this:

### This is out of a database abstraction layer - it just says SELECT count(*) as count FROM vlot_listings WHERE loc_id=1
$pg_links = $dl->select_specific("count(*) as count", "vlot_listings", array( "loc_id"=>$loc_id ), "", "" ); 

### ret_rows contains the number of results
foreach( $pg_links as $d_row ) {
    $ret_rows = $d_row['count'];
}

Probably not the most efficient or up to date way to do this but it works.