Beginners issue with mysql_num_rows()

[David Nikel]

I am attempting to create a login script.

The following snippet of code:

$query = "select * from auth where username='$user name' and
password=passwo rd('$password') ";
$result = mysql_query($qu ery, $db_conn);
$num = mysql_num_rows( $result);
echo $num;

produces the following result:

Warning: mysql_num_rows( ): supplied argument is not a valid MySQL
result resource in prototype4\admi n.php on line 14

I've searched high and low and cannot find a reason why this isn't
working. I am however, a beginner to PHP, so please forgive me if
there's an obvious mistake!

Thanks in advance for any help anyone can give

[Geoff Berrow]

Re: Beginners issue with mysql_num_rows( )

I noticed that Message-ID:
<f43b4914.04022 61159.79fbd94@p osting.google.c om> from David Nikel
contained the following:
[color=blue]
> $query = "select * from auth where username='$user name' and
>password=passw ord('$password' )";
> $result = mysql_query($qu ery, $db_conn);
> $num = mysql_num_rows( $result);
> echo $num;[/color]

Not a PHP question, it's a MYSQL question
could it be password='passw ord($password)' perhaps?

But I also found this, which I don't understand at all...
[color=blue]
>Password hashing in MySQL 4.1.0 differs from hashing in 4.1.1 and up. The 4.1.0 differences are:
>
>Password hashes are 45 bytes long rather than 41 bytes.
>The PASSWORD() function is non-repeatable. That is, with a given argument X, successive calls to PASSWORD(X) generate different results.[/color]


--
Geoff Berrow (put thecat out to email)
It's only Usenet, no one dies.
My opinions, not the committee's, mine.
Simple RFDs http://www.ckdog.co.uk/rfdmaker/

[Pedro Graca]

Re: Beginners issue with mysql_num_rows( )

David Nikel wrote:[color=blue]
> The following snippet of code:
>
> $query = "select * from auth where username='$user name' and
> password=passwo rd('$password') ";
> $result = mysql_query($qu ery, $db_conn);
> $num = mysql_num_rows( $result);
> echo $num;
>
> produces the following result:
>
> Warning: mysql_num_rows( ): supplied argument is not a valid MySQL
> result resource in prototype4\admi n.php on line 14[/color]

This means the mysql_query() call produced /something/ that is not valid
for mysql_num_rows( ) (probably your call has the same effect as
$result = false;
and you can't do mysql_num_rows( false);).
[color=blue]
> I've searched high and low and cannot find a reason why this isn't
> working.[/color]

I can't tell what's wrong either -- but why not let PHP/MySQL tell you?

$result = mysql_query($qu ery, $db_conn) or die(mysql_error () . ' on ' . $query);
[color=blue]
> I am however, a beginner to PHP, so please forgive me if
> there's an obvious mistake![/color]

Maybe $username and $password are not what you think they are?

Are these variables 'sanitized'? You don't want to pass "Mc'Donald" to
the query "as is".

Except for the lack of error-checking (and possibly making the variables
safe) I see nothing wrong.
[color=blue]
> Thanks in advance for any help anyone can give[/color]

You're welcome. Hope this helps.
--
--= my mail box only accepts =--
--= Content-Type: text/plain =--
--= Size below 10001 bytes =--

[Tom Thackrey]

Re: Beginners issue with mysql_num_rows( )


On 26-Feb-2004, cobbler@totalis e.co.uk (David Nikel) wrote:
[color=blue]
> $query = "select * from auth where username='$user name' and
> password=passwo rd('$password') ";
> $result = mysql_query($qu ery, $db_conn);
> $num = mysql_num_rows( $result);
> echo $num;
>
> produces the following result:
>
> Warning: mysql_num_rows( ): supplied argument is not a valid MySQL
> result resource in prototype4\admi n.php on line 14[/color]

The problem is that your query is failing for some reason. That's why the
result resource you passed to mysql_num_rows( ) is invalid.

add the following before the semi-colon on the mysql_query line:
or die($query.' failed because '.mysql_error() )
the message you see will probably be meaningful to you. If not post it here
again an someone will decipher it.

--
Tom Thackrey

https://www.creative-light.com

tom (at) creative (dash) light (dot) com
do NOT send email to jamesbutler@wil lglen.net (it's reserved for spammers)

[David Nikel]

Re: Beginners issue with mysql_num_rows( )

Thanks guys that's given me plenty to go on, appreciated!