How do I set a default query string in my URL? - php

Question

I am trying to build a webapp which shall filter results based on the users current button select and slider choice, I will be achieving this via PHP, SQL and AJAX calls but I need help with sending the correct data to my URL.
DB Dip -
$pType = $_GET['s'];
$fPsiVal = '15000';
$fGpmVal = '10000';
$hPsiVal = '30000';
$hGpmVal = '10000';
$sql = "SELECT * FROM pumps
WHERE pump_type = '$pType'
AND flow_psi <= '$fPsiVal'
AND flow_gpm <= '$fGpmVal'
AND high_psi <= '$hPsiVal'
AND high_gpm <= '$hGpmVal'";
I want to set a default value for pType of ?pType=CONTINUOUS instead of having a static variable, how would I pass this to my URL when the page is called initially?
In order to handle user result filtering I created a form with the method of GET which as I currently understand should send the data to the URL upon for submission, however nothing happens and I am not quite sure what I have done wrong
GET Form -
<form name="pumpCat" action="?s=<?php echo $pType ?>" method="get" align="center">
<div class="btn-group" data-toggle="buttons-radio">
<button type="submit" class="<?php if( $pType == 'intermittent' ){ echo 'active '; } else echo 'noClass '; ?>btn btn-primary waitingUiBut" id="but1" name="s" value="intermittent" action="pumpCat">INTERMITTENT</button>
<button type="submit" class="<?php if( $pType == 'continuous' ){ echo 'active '; } else echo 'noClass '; ?>btn btn-primary waitingUiBut" id="but4" name="s" value="continuous"action="pumpCat">CONTINUOUS</button>
</div>
</form>
Any pointers would be greatly appreciated.

Answer 1

Your action="?pType=" seems to set the default value properly
But, there is no 'href' attribute in a button. Try using an element with proper href and use that to submit the form.

Answer 2

To fix this problem I simply added a query string on the navbar link
<li class=" animateNav <?php if ($pageCat == "Well Service"){ echo "active"; } ?>"><a id="link" href="wellservice.php?s=intermittent">WELL SERVICE</a></li>
and also amended the forms using GET to change the query parameters on the buttons onclick event
<form name="pumpType" action="?s=<?php echo $pType ?>" method="get" align="center">
<div class="btn-group" data-toggle="buttons-radio">
<button type="submit" class="<?php if( $pType == 'intermittent' ){ echo 'active '; } ?>btn btn-primary waitingUiBut" id="but1" name="s" value="intermittent" action="pumpCat">INTERMITTENT</button>
<button type="submit" class="<?php if( $pType == 'continuous' ){ echo 'active '; } ?>btn btn-primary waitingUiBut" id="but4" name="s" value="continuous"action="pumpCat">CONTINUOUS</button>
</div>
</form>

Answer 3

If I understand your goals correctly, I would rethink your apps structure.
You mention you want to use AJAX, so I'd have my SQL query in a separate PHP file, then post the click or slider function value to that file using jQuery, something like:
jQuery
Then update your main HTML file with the returned values.
There is a basic example:
PHP MySQL AJAX