PHP AJAX Interdependent Dropdown List not working

Question

I am trying to create an interdependent drop down list using AJAX and PHP. The problem is that whenever I change the menu in the first drop down list, it does not return the result from the while loop. However, it returns the other statement. To be clear lets discuss this over my codes.

HTML

<tr>
  <th class="col-sm-4">Category</th>
  <td>
    <select id="category" class="form-control">
      <?php while($c = $category->fetch()){ extract($c); ?>
        <option value="<?php echo $cat_id; ?>"><?php echo $cat_name; ?></option>
      <?php } ?>
    </select>
  </td>
</tr>
<tr>
  <th class="col-sm-4">Board</th>
  <td>
    <select id="board" class="form-control">
      <option value="">Select Board</option>
    </select>
  </td>
</tr>

AJAX

$(document).ready(function() {
  $('#category').change(function(){
    var dataString = {
      category: $('#category').val(),
      type: 'loadBoard'
    };
    if(dataString.category > 0){
      $.ajax({
        type: 'post',
        url: 'processes/settings.php',
        data: dataString,
        cache: true,
        success: function(html){
          $('#board').html(html);
        }
      });
    }
  });
});

processes/settings.php

$category = (!empty($_POST['category']))?$_POST['category']:null;
$type = (!empty($_POST['type']))?$_POST['type']:null;

if($_POST){
  if($type == 'loadBoard'){
    $stmt = $pdo->prepare("SELECT brd_id, brd_title FROM forum_boards WHERE brd_cat = :cat");
    $stmt-> bindValue(':cat', $category);
    $stmt-> execute();
    $rc = $stmt->rowCount();

    if($rc > 0){
      while($row = $stmt->fetch()){ extract($row);
        echo "<option value=".$brd_id.">".$brd_name."</option>";
      }
    }else{
      echo $html = "<option value=''>No Board Exists</option>";
    }
  }
}

Here the problem is that when the condition if($rc > 0){ is false it returns the else statement properly. That means it returns No Board Exists properly. But then the condition if($rc > 0){ is true, it does not return the list under the while loop and my select box ends up blank. What is the issue here? Please help.

`PDOStatement::rowCount()` you is not reliable when it comes to select — Masivuye Cokile, Jan 15 '19 at 11:56
Please AVOID `extract()` it is a horrible function that should not be used `` — RiggsFolly, Jan 15 '19 at 11:58
As @MasivuyeCokile said .. [from the manual](http://php.net/manual/en/pdostatement.rowcount.php) ...`If the last SQL statement executed by the associated PDOStatement was a SELECT statement, some databases may return the number of rows returned by that statement. However, this behaviour is not guaranteed for all databases and should not be relied on for portable applications. ` — RiggsFolly, Jan 15 '19 at 12:02
Add [error reporting](http://stackoverflow.com/questions/845021/how-to-get-useful-error-messages-in-php/845025#845025) to the top of your file(s) _while testing_ right after your opening PHP tag for example ` — RiggsFolly, Jan 15 '19 at 12:04
If @RiggsFolly can't solve the problem, he marks it as Duplicate. Great job. — Apple Bux, Jan 15 '19 at 12:22
by the way, it has nothing to do with `Row count with PDO` question. @RiggsFolly — Apple Bux, Jan 15 '19 at 12:22
No its a TYPO and should have been closed and deleted for that reason. But this reason is as good as any — RiggsFolly, Jan 15 '19 at 12:31

score 2 · Accepted Answer · edited Jan 15 '19 at 12:03

2

Change $brd_name to $brd_title

echo "<option value=".$brd_id.">".$brd_name."</option>";
echo "<option value=".$brd_id.">".$brd_title."</option>";

edited Jan 15 '19 at 12:03

RiggsFolly

83,545
20
96
136

answered Jan 15 '19 at 12:02

Blive

88
3

Oh Crap! I was using a wrong field name.. and it slipped below my eyes.. shit I wasted my useful hour behind this.. thanks mate for pointing it out! – Apple Bux Jan 15 '19 at 12:06
For future reference TYPO's should not be answered, a simple comment and then a vote to CLOSE as a TYPO will suffice. This is because TYPO's are of no use to other. – RiggsFolly Jan 15 '19 at 12:33

PHP AJAX Interdependent Dropdown List not working

1 Answers1