PHP Dynamic Form.

[ezb]

I have two slight problems I simply cant find an answer to anywhere, the first, only small.

I have my database printing out items from a database into a select box, this is giving me blank options even though there are none in the database, I remember having this problem before but cant remember how to get around it?

Secondly on the same form I would like another drop down field to change according to what is selected e.g. customer selects product, amount availible is stored in the database so I would like a qty drop down that will display from 1 upto the amount availible.
The Webpage

// connect to the server
   @mysql_connect($host, $username, $password) or die ("Server is Down");
   @mysql_select_db($database) or die ("Database Error");
   $query="SELECT * FROM itemtbl";
$result=mysql_query($query);
 
$num =mysql_numrows($result);
 
mysql_close();
 
?>
<table>
<tr><td>ID</td><td>Session</td><td>Item</td><td>Date</td><td>Qty</td></tr>
<tr><td><form id="orderform" name="orderform" method="post" action=" "><input name="id" type="text" id="id" size="10"></td><td><input name="name" type="text" id="name" size="20"></td><td><select name="product" size="1">
<?php
$i=0;
while ($i < $num){
$id=mysql_result($result,$i,"itemid");
$info=mysql_result($result,$i,"info");
$price=mysql_result($result,$i,"price");
$qty=mysql_result($result,$i,"itemqty");
 
echo "<option value=$id> $info<option>";
 
$i++;
}
?>
</select> 
 
</td><td><input name="date" type="text" id="date" size="20"></td><td><select name="qty" size="1">
  <option value="1">1</option>
  <option value="2">2</option>
  <option value="3">3</option>
  <option value="4">4</option>
  <option value="5">5</option>
  </select> 
 
</td></tr>
<tr><td></td><td></td><td><input type="submit" name="submit" value="Submit"></td><td></td><td><input type="reset" name="submit2" value="Reset"></form></td></tr>
 
</table>
 

[rpnew]

I have two slight problems I simply cant find an answer to anywhere, the first, only small.

I have my database printing out items from a database into a select box, this is giving me blank options even though there are none in the database, I remember having this problem before but cant remember how to get around it?

Secondly on the same form I would like another drop down field to change according to what is selected e.g. customer selects product, amount availible is stored in the database so I would like a qty drop down that will display from 1 upto the amount availible.
The Webpage

// connect to the server
   @mysql_connect($host, $username, $password) or die ("Server is Down");
   @mysql_select_db($database) or die ("Database Error");
   $query="SELECT * FROM itemtbl";
$result=mysql_query($query);
 
$num =mysql_numrows($result);
 
mysql_close();
 
?>
<table>
<tr><td>ID</td><td>Session</td><td>Item</td><td>Date</td><td>Qty</td></tr>
<tr><td><form id="orderform" name="orderform" method="post" action=" "><input name="id" type="text" id="id" size="10"></td><td><input name="name" type="text" id="name" size="20"></td><td><select name="product" size="1">
<?php
$i=0;
while ($i < $num){
$id=mysql_result($result,$i,"itemid");
$info=mysql_result($result,$i,"info");
$price=mysql_result($result,$i,"price");
$qty=mysql_result($result,$i,"itemqty");
 
echo "<option value=$id> $info<option>";
 
$i++;
}
?>
</select> 
 
</td><td><input name="date" type="text" id="date" size="20"></td><td><select name="qty" size="1">
  <option value="1">1</option>
  <option value="2">2</option>
  <option value="3">3</option>
  <option value="4">4</option>
  <option value="5">5</option>
  </select> 
 
</td></tr>
<tr><td></td><td></td><td><input type="submit" name="submit" value="Submit"></td><td></td><td><input type="reset" name="submit2" value="Reset"></form></td></tr>
 
</table>
 

[PHP]

$num =mysql_numrows($result);

[/PHP]

Are you sure that you are using this line... cause according to my knowledge this function is like this...

[PHP]

$num =mysql_num_rows($result);

[/PHP]

Regards,
RP

[ezb]

Thats exactly what I'm using and seems to work fine, well apart from the things listed above..

[Purple]

Hi all,

mysql_numrows() is a deprecated alias of mysql_num_rows().

You should ideally move towards using mysql_num_rows().

Now I am going to take a look at your problem..

Regards Purple

[Purple]

Hi,

not sure if it is a typo but:

[PHP]while ($i < $num) {
$id=mysql_result($result,$i,"itemid");
$info=mysql_result($result,$i,"info");
$price=mysql_result($result,$i,"price");
$qty=mysql_result($result,$i,"itemqty");

echo "<option value=$id> $info<option>";

$i++;
}[/PHP]

should be more like:

[PHP]while ($i < $num) {
$id=mysql_result($result,$i,"itemid");
$info=mysql_result($result,$i,"info");
$price=mysql_result($result,$i,"price");
$qty=mysql_result($result,$i,"itemqty");

echo "<option value=".$id."> ".$info."</option>";

$i++;
}[/PHP]

note the "/" terminator for the option element

Not sure what impact that will have on the code, do the change or confirm typo and post back..

also - as a matter of style, note the changes to the variables on the echo statement - doing it this way allows your IDE to identify them as variables and not just stuff to be echoed to the screen..

Regards Purple

[Purple]

Regarding your second question, you have some choices.

You could do it by building the page using the onchange event to refresh the page and load the second dropdown - this approach will make the page judder on a slow internet connection but can be implemented using 99% PHP.

You could use Ajax which is probably the right way to do it but assumes all of the people using the website have java enabled on their client browsers.

Have you javascript knowledge ?

Regards Purple

[ezb]

note the "/" terminator for the option element

Not sure what impact that will have on the code, do the change or confirm typo and post back..

also - as a matter of style, note the changes to the variables on the echo statement - doing it this way allows your IDE to identify them as variables and not just stuff to be echoed to the screen..

Regards Purple

I knew it would be something stupid like that, yes thats fixed my first problem, well noticed, cheers for that

[ezb]

Regarding your second question, you have some choices.

You could do it by building the page using the onchange event to refresh the page and load the second dropdown - this approach will make the page judder on a slow internet connection but can be implemented using 99% PHP.

You could use Ajax which is probably the right way to do it but assumes all of the people using the website have java enabled on their client browsers.

Have you javascript knowledge ?

Regards Purple

Not really, done bits an bobs of Java, thats about it, never really got into it

[Purple]

Hi,

well I suggest you go the first route,

setup an onchange event on the select to process the form when a selection has been made - within the script test the post values of the first select and if it has been set, make your second select from the DB and build the second dropdown..

Hope that makes sense..

Regards Purple

[ezb]

Cheers for your help, I'll look it up now and give it in a bash, let you know how it turns out, cheers guys

[ezb]

having little look with locating a sufficent example on the internet, just wondering about the syntax, something like

<select name="product" size="1" onChange="$product=$_POST['product'];">
echo "<option value=$id> $info</option>";

how would I need to modify that to get it working

[Purple]

having little look with locating a sufficent example on the internet, just wondering about the syntax, something like

[PHP]<select name="product" size="1" onChange="$product=$_POST['product'];">
echo "<option value=$id> $info</option>";[/PHP]
how would I need to modify that to get it working

Hi ezb,

the onChange event is client side, you need to be in JavaScript

[PHP]<select name="product" size="1" onChange="javascript:refresh_win();">
<?php
echo "<option value=$id> $info</option>";
?>[/PHP]
with a javascript function called refresh_win() which presses a submit button on the screen - you will need the form to post to itself to make this work..

Regards Purple

[Purple]

oh and, please use code tags when posting code, no matter how small..

MODERATOR

I can't change your post cause I don't moderate this forum, I am sure one of the php mods will get on this...

[Purple]

Hi,

function refresh_win()
{
    document.formname.submit.click();
}

formname needs to be changed to the name of your form
assumes you have a button called submit - change to name of button if not.

Regards Purple

[ezb]

Hi ezb,

the onChange event is client side, you need to be in JavaScript

[PHP]<select name="product" size="1" onChange="javascript:refresh_win();">
<?php
echo "<option value=$id> $info</option>";
?>[/PHP]
with a javascript function called refresh_win() which presses a submit button on the screen - you will need the form to post to itself to make this work..

Regards Purple

Sorry about that, was not intending on adding proper code so simply didnt bother with code tags, edited it accordingly.
The touble with this being I would like to submit the form into a database once I have the selected information, how can I do this if I'm porting the form to its self in order to this variable?

[Purple]

Hi ezb,

you do this by building code block which run based on which post values are set

so :

[PHP]<?php
if (isset($_POST['first_select']) and $_POST['first_select'] <> "default value" and !isset($_POST['second_select']) ) {
//
do the code to build the second select
//
}
elseif(isset($_POST['first_select']) and $_POST['first_select'] <> "default value" and isset($_POST['second_select']) and $_POST['second_select'] <> "default value" ) {
//
do the code to save the data to the database
//
}
?>[/PHP]

does that help ?

Purple

[ezb]

sorry about this but the above doesnt make much snece to me.

I've got the java script working but as I though, when I select an option it basicly refreshes the form, taking all the items back to the default, was wondering if theres a way to get the same result but keeping what the user has selected in the form, purhaps taking the selected into a variable and using them as default when the form submits somehow?

[Purple]

Hi,

as with all of these things, there are a number of ways to achieve this..

simplest is prob using sessions so :

[PHP]<?php
session_start(); // this needs to be executed before anything is sent to the browser - including any white space
if (!isset$_SESSION['form_vars']) session_register('form_vars');
if(!empty($_POST['variable']) $_SESSION['form_vars']['variable'] = $_POST['variable']; // this needs to be done for all vars on the form
else $_SESSION['form_vars']['variable'] = null;
// now in the form we can set the field values to $_SESSION['form_vars']
['variable'] and this will be maintained across submissions of the form.
//*
//* build the form here
//*
// when its processed you need to do the following to clear the variables:
unset($_SESSION['form_vars'][);
// its also good practise to tidy the session record too using:
session_destroy(); // but only after you have saved your values...

?>[/PHP]

Does that help ?

Questions ?