Linking pages in PHP and PostgresQL

BBDan

In Page 1 that I have the below code:

if($col==1)
{
$OutCtrl=1;
//echo "<a href=webpurchase1.php>Company Name</a> ";
echo "<a href=\"webpurchase1.php?sort=companyname\">Company Name</a> ";
}

Then in Page 2, I have the following:

if($_GET['sort']==companyname)
{
if($sortCompany==0)
{

$query=" SELECT * FROM webpurchases ORDER BY companyname DESC";
$sortCompany=1;
}
else
{

$query=" SELECT * FROM webpurchases ORDER BY companyname ASC ";
$sortCompany=0;
}

$OutCtrl=0;
}

The table is suppose to sort itself alternatively between ASC and DESC everytime I click on the link. However, using echo, I found that the $sortCompany does not have any values at all at the start, not even zero. What does it mean?

Thanks

dalecosp

Variables have NULL values if they have not yet been created...

You might look at [man]if_exist/man and [man]is_null/man for more info ...

BBDan

The variable $sortCompany is a NULL initially, and does not have any value. What I don't understand is why wouldn't it get "1" after the first or second click on the "Company Name" link and stored that value, or rather why was the $sortCompany value reset to NULL? I did not declare that variable elsewhere and was wondering has the problem got anything to do with the browser engine?

dalecosp

click on the "Company Name" link and stored that value

I'm a tad thick at times, but it seems like you believe that $sortCompany should have global scope. Unless you have specifically instructed your installation of PHP to automagically place all variables in the global scope, then Page 2 doesn't care in the least whether anyone's clicked on anything on Page 1 when evaluating local variables...

Read #1 in this forum's FAQ for more details ...

BBDan

$sortCompany is not intended to be a global variable; it is only intended to hold a value in page 2 such that the value will change every time page 2 is accessed. After reading the FAQ#1), it seems to be that those syntax in the FAQ are for variables that appears in both pages, or for data entered onto a text box.

I'm not really sure that I understand the FAQ completely though.

dalecosp

A script cannot "hold" a value and wait for a new page access all by itself. Each script is compiled by PHP at the time of the HTTP request. As far as PHP is concerned, once the script is run, it (the script itself) doesn't even exist anymore until called upon the next time...

If you wish to store information about the state of the last table sort across multiple page loads, I would advise you to look into either setting a marker in the db, using a session variable, using cookies, or writing the sort status to a text file and reading that file upon each page load. An alternative might be to pass a $last_sort_state variable around from script to script as the user navigates the site, but that's not real different from the session concept ... though it would be an easy code.

echo "<a href=\"webpurchase1.php?sort=companyname&sortCompany=$OutCtrl\">";

BBDan

Thanks...Got it!