Is it possible to continue with the rest of the code on an mysql error?

[flit]

Hi there,

 

I don't know how to explain this:

I have some id's saved in a session

I used the foreach (idArray as $id) to execute the following mysql query

 

$query = "SELECT * FROM books where id=$id";

 

When I echo $id I see 1,2,3, and the last , makes mysql give me an error

Is it possible to continue with the rest of my code after an mysql error or is there some

other way to prevent this? I want to get rid of the , so the code can continue

[p2grace]

If there's always an extra comma at the end, you could use substr to remove it.

 

<?php
$id = "1,2,3,";
$id = substr($id,0,-1);
echo $id; // will echo 1,2,3 (no extra comma)
?>

[Barand]

trim() might be safer. If there isn't a trailing comma substr($id,0,-1) will leave you with one.

<?php 

$id = "1,2,3,";
$id = trim ($id, ',');
echo $id; // will echo 1,2,3 (no extra comma)

?>

[p2grace]

Ahh I didn't know trim removed anything except spaces, good to know.  Thanks Barand

[flit]

Thanks both solutions worked, but now I have another problem

When I run the code I do not receive an error message any more but the

output is not what I wanted. I receive something like this

 

Title:  //without anything

Author: //without anything

ISBN: //without anything

 

[Barand]

your code?

[flit]

foreach ($idArray as $id);

{

$query = "SELECT * FROM books where id=$id";

$result = mysql_query($query) or $id = trim($id, ',');

$row = mysql_fetch_array($result);

 

echo "Title: ".$row['title'];

echo "<br>";

echo "Author : ".$row['author'];

echo "<br>";

echo "ISBN: ".$row['isbn'];

 

.........

 

 

 

[flit]

Title:  //without anything

Author: //without anything

ISBN: //without anything

 

............this happens when I press on reload/refresh

[p2grace]

Where's the idarray coming from?

[Barand]

$result = mysql_query($query) or $id = trim($id, ',');

??? ??? ???

 

what does

echo '<pre>', print_r($idArray , 1) , '</pre>';

output

[flit]

Where does he $IdArray come from???

 

->

$id = $_SESSION['sessionvar'];

idArray = explode(',' , $id);

 

Did you meant this  part??

[phpSensei]

$idArray comes from your session you exploded after each comma, then you put it in your foreach ($idArray as $id), so print_r($idArray) before the foreach, or even after, but not in it.

 

 

[Barand]

 

what does

echo '<pre>', print_r($idArray , 1) , '</pre>';

output

 

Still waiting for an answer to that one

[flit]

Ow sorry Barrand. I don't understand what you mean.

 

But the program is supposed to run like this

There are some session id's in a session file

sessionvar|s:7:"3,2,1";

 

The code creates a session id

-> foreach

The code echos for every id in the session info from an msql data

 

echo "Title :".$row['id'];

 

But when I press to refresh in my browser, there comes some

info, but no mysql data

 

I don't know if I understood you correctly but is this what you meant??

[Barand]

Simple enough. Put this line of code in your program and tell us what it outputs

echo '<pre>', print_r($idArray , 1) , '</pre>';

[flit]

It outputs,

 

1 Connected Successfully Array([0]=>1[1] =>1)

 

 

-->

Array
(
      [0] => 1
      [1] => 1
)

The program works perfectly until I press refresh

Then comes blank data

 

 

[p2grace]

Are the sessions being lost for some reason on refresh?

[flit]

It outputs,

 

1 Connected Successfully Array([0]=>1[1] =>1)

 

 

-->

Array

(

      [0] => 1

      [1] => 1

      [2] =>

      [3] =>

 

)

 

The program works fine until I refresh the page

 

 

 

[flit]

I really don't know.

 

Can't I trim that info too??

[flit]

When I open the session file I see

 

sessionvar|s:8:"1,2,3,,,";

 

I think that this might have caused the problem, anyone know a sulotion for this???

[phpSensei]

When I open the session file I see

 

sessionvar|s:8:"1,2,3,,,";

 

I think that this might have caused the problem, anyone know a sulotion for this???

 

Are you adding to the sessions?

 

How are you inserting the data to the $_SESSION

[flit]

I am inserting data into the session via the url

 

<a href="books.php?action=add&id=1">

 

When I open http://localhost/books.php it inserts some data that I do not want in the page

When I press refresh it inserts it again.