PHP - Handling Php With Large Database

Hi ..am new to PHP and am using it to solve some mathematical problems which require extensive computation.

Following is a code to solve a problem:
Code: [Select]
<?php

$num =1;
$n =0;
$temp = 0;
$count =0;
$Final =0;

While( $num < [color=orange]1000000)[/color]
{
   $n = $num;
       while($n >1)
         {

            if(( $n % 2) == 0)
              {
                $n = $n/2;
                $temp++;
              }
             
             else
              {
                $n =3*$n +1;
                $temp++;
              }
           }

     If($temp > $count)
          {
            $count =$temp;
            $Final =$num;
          }


      $num++;
      $temp =0;
}

  echo $Final;
  echo "<BR>";
  echo $count;

?>      
I am running into "Maximum execution time of 30 seconds exceeded" error...its happening coz of the number 1 million...the code wrks fine for 100,1000,10000 and 100000...but breaks down @ 1000000.....is there any way to solve this situation...or PHP is not capable of handling huge numbers?

please help...am stuck with this even though am so close to solving the prob.

Thanks
Abhijeet

Hi,

I'm a beginner in PHP OOP and I'm with some doubts about the correct way of handling errors in PHP.

Look at this function for example:


public function deleteFileFromDisk($fileNameToBeDeleted) {

    $handle = unlink($fileNameToBeDeleted);

    if (!$handle) {
        $result = "(this->deleteFileFromDisk) - Error, " . $fileNameToBeDeleted . " not deleted.";
    } else {
        $result = "(this->deleteFileFromDisk) - Success, " . $fileNameToBeDeleted . " deleted.";
    }
    return $result;
}


Is this the correct way of doing it, or I can do better than this?

Let me add some details of what I'm achieving...

I'm running class methods, and I need to control errors in the process. If any call to the object throw an error I need to catch, stop all the process and send an e-mail with the error.

Here are the object interactions:


$testar_classe = new geoIpImportCSV('geolitecity', 'http://geolite.maxmind.com/download/geoip/database/GeoLiteCity_CSV/');
$testar_classe->downloadAndSaveFile('./', $testar_classe->obtainDownloadFileName());
$testar_classe->uncompressZipFile($testar_classe->obtainDownloadFileName(), '.');
$testar_classe->deleteLine(1, 'GeoLiteCity-Location.csv');               
$testar_classe->deleteLine(1, 'GeoLiteCity-Blocks.csv');
$testar_classe->deleteDataFromTable('tabela1');
$testar_classe->deleteDataFromTable('tabela2');
$testar_classe->insertLinesToDb('GeoLiteCity-Location.csv', 'tabela1');
$testar_classe->insertLinesToDb('GeoLiteCity-Blocks.csv', 'tabela2');
$testar_classe->deleteFileFromDisk($testar_classe->obtainDownloadFileName());
$testar_classe->deleteFileFromDisk('GeoLiteCity-Blocks.csv');
$testar_classe->deleteFileFromDisk('GeoLiteCity-Location.csv'); 


Which is the best way of handle this? Create a new method to take care of the exceptions? There are any examples on how to do this?

Best Regards.

Hey Guys, Been coding PHP for a while but I always wonder about the right way of doing things. I am building an online community which I want to display to members and non-members. With this each screen will have options that are available for members only. I have set up session variables once a user logged in but its getting really old having to nest if statements on ISSET then again to check the values in the variables if it is set. See example below.   Question 1. Is it ok to session_start(); for all site visitors? Question 2. If Q.1 is ok then is it ok to set all the session variables upfront with blank values as placeholders. This would eliminate the need for ISSET.

if (ISSET($_SESSION['On'])) {
	if (in_array($GroupID, $_SESSION['Groups'])) {
		$IsMember = 1;
		} 
	else {$IsMember = 0;}
	}
else {$IsMember = 0;}

Just wanted to get your  thoughts on this.   Thank you, Jeremy

This doesn't work. Based off what I have seen online, it is suppose to.

Basically, this is what I tried, and the quote is what was returned. I have no idea how to get this to work. It should have been pretty standard
based off of the PHP documentation. The Xpath idea I got from someone else. Either way if I try to use find element by id or tag name it still
returns an empty array, no matter what.

Any advice on what I am doing wrong is appreciated. It doesn't matter what URL I try, none of them seem to work.
Code: [Select]
<?php
$school_data = file_get_contents('http://www.infotechnologist.biz');
$doc = new DOMDocument();
$doc->validateOnParse = true;
$doc->loadHTML($school_data);
$xpath = new DOMXPath($doc);
$tags = $xpath->query('div');
echo '<pre>';
print_r($tags);
echo '</pre>';
?>
Quote

DOMNodeList Object
(
)

Hi
I'm completely new to error handling in PHP and wanted to ask whether I'm doing it right and, if not, what the right way would look like

class DBConnection {

public function execute($sql) {

$query = @pg_query($this->dbconn, $this->prepare($sql));

try {

if (!$query) {

throw new DBException();

}

} catch (DBException $e) {

echo "Query execution failed";

exit;

}

}
}

A form needs to get answers of math quiz, returning numbers, up to 2 digits after the point.
In all form examples I noticed the usage of:  Code: [Select]
...<input type="text" name="name" /...
Cant it be a number? floating or integer? why "text" ?

Also, can I limit the form to accept numerical input only or would I need to learn Ajax for that?

Once I have the answer, I need to compare it to the correct answer. The method I have in mind is to multiply the answer and the correct one by 100 and compare the integer part. Is there a pre-made function that can do the same?

Whats the best way to handle database errors.

I been using ob_start() stuff to run the code and if a database connection error occurs an variable $error turns to 1 and it displays the error code instead of the normal page that should be displayed when no errors occur.

It works but I want to know if there is any better way to manage a db connection error while running a script.

Also, how do you manage a problem when like 3 queries are ran to setup a new user account and the last one fails because the db connection drops or something, how would you go about handling a 2/3 query successful?

I'm really stuck on how to manage errors if a db connection fails after the first connection is successful.

I am inserting last names into the database using mysql_real_escape_string(), and outputting the data into a textbox using addslashes().

When I try to display O'Brian "O\" is displayed in the text box.

The name is saved corretly as O'Brian in the database.

I am printing the string like this:

Code: [Select]
echo "<input type='text' value='" . addslashes($customer['lName']) . "' blah blah...";

anybody have any ideas?

I have set an SQL field as unique so that duplicates can't be entered, however rather then having the page error out and show the Error: Duplicate entry 'entry' for key 'field' I would like to be able to have a little div appear and say something like "this entry already exists" I already have it set to show that the item has been added but I have no idea were to start to make this work.

Any ideas?

Thanks,
Jim

I have a prepared statement that returns an Article from my database.  It then binds the results-set to variables.

Most of the fields in the query are "required", so I *assume* that I am guaranteed to always get values back for those fields...

Is that presumptuous?

Here is a snippet of my code...

// Execute query.
mysqli_stmt_execute($stmt);

// Store results.
mysqli_stmt_store_result($stmt);

// Check # of Records Returned.
if (mysqli_stmt_num_rows($stmt)==1){
// Article was Found.
$articleExists = TRUE;

// Bind result-set to variables.
mysqli_stmt_bind_result($stmt, $articleID, $title, $description, $keywords, 
$heading, $subHeading, $publishedOn, $author,
$body, $referenceListing, $endnoteListing);

// Fetch record.
mysqli_stmt_fetch($stmt);

// Close prepared statement.
mysqli_stmt_close($stmt); // ????



Is it sufficient to have code like this...

Code: [Select]
<title><?php echo $title; ?></title>
...or do I need more error-handling??

Hope that makes sense?!

Thanks,


Debbie

Hi,

I have an HTML form created using Dreamweaver and now I need a script to handle the form processing. Basically what I need is for the form data received from the webpage to be organized in an email and then sent to me. I would also like to display a thank you message in the browser so the user knows it was received. I was planning to do this using CGI but a colleague suggested that CGI is old school and nowadays a developer would use PHP for this task. Is PHP the right solution for this project?

The examples I have found so far always include the HTML for the form and the script needed to handle it in one file. In my case, I have an HTML form already in place and need it to work with a script to perform the email function. I know I need to set "Action=" on my webpage to point to the PHP script but what would the code look like if no HTML is needed? I hope this makes sense...

Thanks for your help!
Rob

Hello,
Am writing a script that involves user input.
Take an example: a user fills in a wrong username or password at the page login.php, my login processor (processor.php) detects it, how is the error "WRONG USERNAME OR PASSWORD" supposed to be transferred back to login.php.
So far I have been using a session variable to transfer the error but am sure there is a better way to do this without displaying the error on processor.php itself.

Thanx in advance

Hey everyone!   I have a question about handling video files. Are there classes available for handling videos? I've found classes to handle images and I was wondering if there is something similar for videos.   I'm asking because I want to allow users to upload videos, but I want to reduce their resolution (take up less space). The video is intended to play in a small section on the page, so it doesn't require high resolution.   I'll appreciate any help. Thanks!

My script displays results until I hit an error.  I continually get fatal timeout errors that I am unable to handle or ignore.  Yes I googled and found the custom error handler AND the simpler try/catch.  Still cant figure it out...
It has been 1 hour of playing with this without success so I have to ask  .  Please help.  thanks : )

Code: [Select]
try
{
if(($result=shell_exec("$commandLine")) == false)
{
echo "------>error";
throw new Exception;
}
else
{
echo "---->good";
}
}
catch (Exception $e)
{
echo "@@@__>exception caught";
}

want something like:
Code: [Select]
date('F j, Y, g:i a')
but in central timezone, how do I change the timezone to central?