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Jul 5th, 2010

PHP check variable change

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Hi,

What i have is a variable that is getting updated periodically and i've set the php script to refresh itself every 30 seconds to run a mysql query updating a db, this is good but if this value isnt changing from the source i get duplicate records in the db, how do i check the value of the variable with php and only execute the query when the variable has changed value?

Thanks

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benhowdle89

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Jul 5th, 2010

Re: PHP check variable change

Before generating the next value set your variable to clear or NULL after updating the db, and before updating check whether variable is clear or NULL skip the update process.

rajarajan07

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Jul 5th, 2010

Re: PHP check variable change

post your code.

raju_boini525

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Jul 5th, 2010

Re: PHP check variable change

That sounds perfect, would you mind putting a bit of sample code together please?

This is my code so far:

PHP Syntax (Toggle Plain Text)
<?php
header('refresh:30; url=pachube.php');
require_once( '/pachube_php_library/pachube_functions.php' );
$api_key = "xxxxxxxxxxxxxxxxx";
$pachube = new Pachube($api_key);
$feed = xxxxx;
$data = $pachube->retrieveData ( $feed, "csv" );
$array = explode(',', $data, 5);
$value = $array[0];
echo $value;
 
	//Connect to database
	$opendb = mysql_connect("localhost", "root", "") or mysql_error("Could not connect to database");
    mysql_select_db("test");
 
    if ($opendb)
		{
     	mysql_query(" INSERT INTO arduino (data) VALUES ($value)");
		mysql_close($opendb);
		}
 
?>
<?php
header('refresh:30; url=pachube.php');
require_once( '/pachube_php_library/pachube_functions.php' );
$api_key = "xxxxxxxxxxxxxxxxx";
$pachube = new Pachube($api_key);
$feed = xxxxx;
$data = $pachube->retrieveData ( $feed, "csv" );
$array = explode(',', $data, 5);
$value = $array[0];
echo $value;

	//Connect to database
	$opendb = mysql_connect("localhost", "root", "") or mysql_error("Could not connect to database");
    mysql_select_db("test");

    if ($opendb)
		{
     	mysql_query(" INSERT INTO arduino (data) VALUES ($value)");
		mysql_close($opendb);
		}
		
?>

So i'm guessing i would need to put some sort of "if" statement above the mysql query??

Thanks

benhowdle89

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since Jun 2010

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Jul 5th, 2010

Re: PHP check variable change

PHP Syntax (Toggle Plain Text)
<?php
header('refresh:30; url=pachube.php');
require_once( '/pachube_php_library/pachube_functions.php' );
$api_key = "xxxxxxxxxxxxxxxxx";
$pachube = new Pachube($api_key);
$feed = xxxxx;
$data = $pachube->retrieveData ( $feed, "csv" );
$array = explode(',', $data, 5);
$value = $array[0];
echo $value;
if (isset($value) && !empty($value) && $value != NULL)
{
	//Connect to database
	$opendb = mysql_connect("localhost", "root", "") or mysql_error("Could not connect to database");
    mysql_select_db("test");
    if ($opendb)
		{
     	mysql_query(" INSERT INTO arduino (data) VALUES ($value)");
		mysql_close($opendb);
		}
	$value = '';
} else echo "No value is set";
?>
<?php
header('refresh:30; url=pachube.php');
require_once( '/pachube_php_library/pachube_functions.php' );
$api_key = "xxxxxxxxxxxxxxxxx";
$pachube = new Pachube($api_key);
$feed = xxxxx;
$data = $pachube->retrieveData ( $feed, "csv" );
$array = explode(',', $data, 5);
$value = $array[0];
echo $value;
if (isset($value) && !empty($value) && $value != NULL)
{
	//Connect to database
	$opendb = mysql_connect("localhost", "root", "") or mysql_error("Could not connect to database");
    mysql_select_db("test");
    if ($opendb)
		{
     	mysql_query(" INSERT INTO arduino (data) VALUES ($value)");
		mysql_close($opendb);
		}
	$value = '';
} else echo "No value is set";
?>

rajarajan07

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Jul 5th, 2010

Re: PHP check variable change

Brilliant, Thanks so much!!!

benhowdle89

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Jul 5th, 2010

Re: PHP check variable change

Always welcome! Please mark the thread as solved.

rajarajan07

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