Passing Parameters

[AlGale]

Right, I had some excellent help from some of you guys before - so I thought I`d ask again...

I have some code which passes the selection of a dynamically created dropdown list onto a redirection page, thus:

      </p>
    </div>
    <form name="formname" method="get" action="redirect.php">
      <div align="center"> 
        <select name="redirect" >

<?php
$cursor = mysql_query("select distinct County, HRef from Main order by County asc");
if (!$cursor)
{
echo("<H3>MySQL error: " . mysql_error() . "</H3>");
exit();
}
while ( $row = mysql_fetch_array($cursor) )

{
if ($row["County"] <> "Advertisement")
{
print ("<option value=\"" . $row["HRef"] . "\">" . $row["County"] . "</option> ");
}
}
?>
</select>
<input type="submit" value="Go!">
</div>
</form>

With the coding on the redirection page like this:

<?php

header ("Location: " . $_GET['redirect']);

?>

My question is twofold. Firstly, I cant see where the HRef is actually passed to $_GET - why is it that and not County? because its a value?

Secondly, on other pages I want to change this code to perfom a different function. I want another dynamically generated dropdown box, (this time of districts), and the resulting selection must be passed onto a MySQL query so that only those districts are pulled from the database. I`m sure the answer to the first question will help me with this. If possible I want this to be done on the same page.

Any help will be very gratefully received. Thanks!🙂

[jpmoriarty]

in answer to your first, the form passes the variable name and the value as assigned in the HTML code (ie, in your option you have the HTML code "value", which is your href). Ie it's the way HTML works and is programmed to work.

for your second you just need to search the db based on the values that are passed to it, which will again come from the value defined in the option tag.

[AlGale]

Hi John.

Thanks for the reply.

Obviously I will need to change the form action though, as I am not re-directing to another page, but just assigning a value to a variable which I will then use in my next MySQL query.

So, which action do I use? $_SERVER[PHP_SELF] doesn`t seem to work, but I assume it must be a PHP_SELF action I require? Thanks

[jpmoriarty]

well you've got to set teh action to which ever page it is that contains the code to deal with the input you've just given it. so if that's the page that the form is on (lets say you call it form.php), then I'd just set the action to "form.php": i dont see much need for the use of more php when you can just type it in yourself.

If you do that, then you'll need to add code to the page so that it recognises that variables have been passed to it, and then does something with those variables (in this case adds it to a query or whatever).

I always find it gets confusing quite quickly when you're calling the same page from the form, and so like to plan what's going to happen and when before - otherwise you'll end up with a page and you'll never quite be sure what it's going to do and when

[AlGale]

EEEKK! Clearly this is not going to be as easy as I first thought.

If I create a variable and call it $District for instance and set it to have a default of say, "Bracknell", wont it be reset back to that default every time the page is reloaded after actioning the form?

[AlGale]

Right, I think I`m getting there. What I could do with some help on, if anybody knows, is how I use $_Get to bring in the value contained within the $row[HRef] of the selected option.

Any ideas anyone?

[jpmoriarty]

well you've given it the name "redirect", so all you'd do is:

$_GET['redirect']

and it should be there.

NOTE: IT IS NOT $get, it's $GET: it's case sensitive, and you wont get what you want if you dont ask for it properly!

[AlGale]

John,

That`s brilliant. You have cleared up quite a few points for me there. Thanks.

I have tried to use:

$cursor= mysql_query("select Restaurant, Address, County, District, PC, Phone, Hyperlink, HperlinkAdd from Main where Main.District = '" . $_GET["redirect"] . "' order by District asc");

But it doesn`t seem to do anything. It should then print out a table full of the selected items, but the page just refreshes exactly the same, ie the table is blank.

The MySQL codes runs fine - there is no errors anyway. Am I missing something else?

Thanks for your help!

[AlGale]

John,

Don`t worry. It was me again. Case sensitive! It all works now. Thanks again for your help.

Al