Problem: expects parameter 1 to be resource

[Avasulthiris]

Hi all,

I've been hitting the same problem over and over in my development. Sometimes when i do a MySQL query I keep getting the error
Warning: mysql_fetch_row() expects parameter 1 to be resource.

I don't understand why. What does this error mean, am I doing something wrong? I've googled it but I just get pages with the same error...

I'm using php 5.3, it's definitely not my mysql statement. I'm lost >.<

I even simplify my query code and still the same problem. The general code look something like this:

require "dbconn.php";
$id=$_POST['id'];
$checkquery = "SELECT * FROM table WHERE id = '$id'";
$checkresults = mysql_query($checkquery);
$row = mysql_fetch_row ($checkresults);

It crashes on the last line :S

[ShawnCplus]

Take a look at the FAQ that is stickied, follow those instructions and then if it still doesn't work repost your code along with the new errors

[Avasulthiris]

Still cant find anything. What do you mean by stickied?

The code is literally as simple as what I have above in my original thread. I'm just trying to understand the error.

It's been popping up everywhere. Even with the most simple code. It's unhappy with the mysql_fetch_row command.

Sometimes it works if i copy the code into a new file. I thought I might be using reserved words in mysql, but i'm definitely not. The database also has nothing weird in. It's just being weird.

And I have to finish this system by tomorrow night >.<
*is stressing*

What does that error mean? How is $checkresults not a resource?

[ShawnCplus]

require "dbconn.php";
$id=$_POST['id'];
$checkquery = "SELECT * FROM table WHERE id = '$id'";
$checkresults = mysql_query($checkquery);
var_dump($checkresults);
die();
$row = mysql_fetch_row ($checkresults);

Do that and post the output

[dasatti]

require "dbconn.php";
$id=$_POST['id'];
$checkquery = "SELECT * FROM table WHERE id = '$id'";
$checkresults = mysql_query($checkquery);
$row = mysql_fetch_row ($checkresults);require "dbconn.php";
$id=$_POST['id'];
$checkquery = "SELECT * FROM table WHERE id = '$id'";
$checkresults = mysql_query($checkquery);
if($checkresults && mysql_num_rows($checkresults)>0)
{
$row = mysql_fetch_row ($checkresults);
}
else
{
if(!$checkresults)
echo "Error in query: ".mysql_error();
else
echo "No record Found";
}

[Avasulthiris]

I changed my code entirely throughout the night and now that specific problem is gone.

I do still occasionally get the same error, I just dont have an example of it right now. When i printf the error it comes out blank. It's been boggling me for a while.

I will post an example as soon as I run into it again

[Avasulthiris]

Here we go, its happening in 4 different places now:

This is the error:

Warning: mysql_fetch_row() expects parameter 1 to be resource, boolean given in C:\wamp\www\EIRMSv2\pages\upload_rename_ac.php on line 135

This is they code in that section(lines 130-135):

require "dbconn.php";
			
			$checkquery = "SELECT * FROM flowchart WHERE id = '$id'";
			$checkresults = mysql_query($checkquery);
			
			$row = mysql_fetch_row ($checkresults);

My dbconn file definitely works. My values are posted correctly...

If i do a var_dump it returns bool(false). I dont know what that means?

[dasatti]

You must use if($checkresults) check out side the statement $row = mysql_fetch_row ($checkresults);

$checkquery = "SELECT * FROM flowchart WHERE id = '$id'";
$checkresults = mysql_query($checkquery);
if($checkresults)
{
	$row = mysql_fetch_row ($checkresults);
}

The reason is when it encounters some invalid $id, the mysql_query() function does not return valid result set. You can use mysql_error() to find out the reason why returned resultset is not valid

[dasatti]

One of the reasons that invalid result set is returned could be you are comparing a string value with an integer type field in database.

Make sure that if the id field in flowchart table is int then use this statement $checkquery = "SELECT * FROM flowchart WHERE id = $id"; instead of $checkquery = "SELECT * FROM flowchart WHERE id = '$id'";

[Avasulthiris]

Another module of the project im working on is mysqli instead of mysql. Could it be that that is causing the problems? That module uses its own dbconn file though so i dunno why its having this issue

[Avasulthiris]

hi dassati,

i tried that, that is not the problem unfortunately. if only it was so simple. the sql runs in phpmyadmin. the single quotes don't matter.

[Avasulthiris]

it is not the $id. the code is set to always give a valid id. problem is still there if i say $id=1;

that is also not the problem. im pretty sure its compatibility issues between mysql and mysqli both selecting the database, even if its in different places. I dont think the server likes it when i select the same database two different ways. I just need someone who understands this to explain it to me

[dasatti]

make sure that close mysqli connection before playing with simple mysql and vise versa

[Avasulthiris]

Thats exactly what I plan on doing thanks. I hope thats the problem though, I havn't really seen this before. It's a lot of work to go change all the queries in the whole project >.< haha

I will keep looking to see if it comes up again

thanks

[scyfox]

require "dbconn.php";
$id=$_POST['id'];
$checkquery = "SELECT * FROM table WHERE id = '$id'";
$checkresults = mysql_query($checkquery);
$row = mysql_fetch_row ($checkresults);

It crashes on the last line :S

As Daft Punk says... harder, better, faster, stronger.... try this.

require "dbconn.php";
$id=$_POST['id'];
$checkquery = "SELECT * FROM table WHERE id = '$id'";
$checkresults = mysql_query($checkquery);
if (!empty($checkresults)) {
       $row = mysql_fetch_row ($checkresults);
} else {
   echo "Issues trying to fetch results. Check the error-->" . mysql_error();
die();
}

If Empty checks if the array comes with some data no matter if it is boolean or not, so if the query is wrong or you ain't got nothing inside de bd, it skips the "fetch_array" part and goes straight to the error handling part.

Really useful and clutter free.

Silla!

[network18]

no absolutely not, mysqli is just the improved extension of mysql set of functions.It should not make any harms.
Also post your code dbconn.php for others to see, maybe it needs some improvements.

[dark.matter]

i got this error when my SQL statement was incorrect. The field names were incorrectly spelled.

[jitu99]

well i was getting the same error............in my case the spelling of the column name in my code and the database was different...the colum name in the database was tilte and in the code it was title....so i had to change the column name in the database to title.......

[vaultdweller123]

What if your query return an empty recordset?

[JRM]

One of the reasons that invalid result set is returned could be you are comparing a string value with an integer type field in database.

Make sure that if the id field in flowchart table is int then use this statement $checkquery = "SELECT * FROM flowchart WHERE id = $id"; instead of $checkquery = "SELECT * FROM flowchart WHERE id = '$id'";

I think you are on the right track, but the variable needs to be appended like so:

$checkquery = "SELECT * FROM flowchart WHERE id = ". $id ;