generating buttons to update inventory in php - php

Question

Okay so I'm a bit lost here as I'm very new to AJAX and fairly new to PHP. So I have an inventory management system build with phpmyadmin and wamp. The registration/ log in system works great. so when the user logs in a table of all inventory is generated on screen, along with a button next to each inventory item that allows the current user to check in or check out an item. the buttons are all generated and I gave them a unique id using php and the code looks like this.
<table class = "table">
<thead>
<tr>
<td><center><strong>Item Id</strong></center> </td>
<td><center><strong>Item Description</strong></center> </td>
<td><center><strong>Item Type</strong> </center></td>
<td><center><strong>Availability</strong></center></td>
<td><center><strong>Name</strong></center></td>
<td><center><strong>Check in/out button</strong></center></td>
</tr>
</thead>
<tbody>
<?php
mysql_select_db('inventory management system');
$query="SELECT * FROM inventory";
$results = mysql_query($query);
$a = 0;
while($row = mysql_fetch_array($results)) {
$a++;
echo '<script type = "text/javascript">c++;</script>'
?>
<tr>
<td><center><?php echo $row['item_id']?></center></td>
<td><center><?php echo $row['item_desc']?></center></td>
<td><center><?php echo $row['item_type']?></center></td>
<td><center><?php echo $row['availability_status']?></center></td>
<td><center><?php echo $row['name']?></center></td>
<td><center><?php
if(is_null($row['name'])){
//this is what is generating each button with a unique id echo '<input class="btn btn-default" type="submit" value="Check Out" id = "<?php echo $a; ?>" onclick="<?php ?>">';
}else if(!is_null($row['name'])){
echo '<input class="btn btn-default" type="submit" value="Check In" id = "<?php echo $a; ?>" onclick="updateinventory()">';
}
?></center></td>
</tr>
<?php
}
?>
</tbody>
</table>
so now when the user clicks a button, it updates the database to set the name field to null signifying that nobody has the item checked out, that way another user can sign in and check out an item in the inventory. I'm really struggling and have tried everything from on click methods (which for some reason I couldn't get to work) to plenty of things with ajax and php.. and I cant get a seemingly simple feature to work... Thank you for any possible help.

Answer 1

You have already opened php tags so change
echo '<input class="btn btn-default" type="submit" value="Check In" id =
"<?php echo $a; ?>" onclick="updateinventory()">';
to
echo "<input class='btn btn-default' type='submit' value='Check In'
id ='$a' onclick='updateinventory()'>";
Similarly remove php tags from IF since php starting tags have been written above.
type="submit" this will directly submit the page, and you probably need to make it button so that you may call javascript function that will eventually call ajax.