Question

I’m making a website, where I should be able to delete some brands from a database, the brands is stored in categories.

In my form, I have a that echo’s out all the categories in my database.

The next should then contain all brands that is within’ my selected category.

My categories contains a categoryID which is the value of the in the first dropdown – The brands is having it’s own ID, but also having the categoryID, from the category they’re in.

How would you do this? – And can you give an example, it might need javascript or jquery, which is fine with me.

This is my code:

     <form action="deleteBrand.php" method="post">
        <fieldset class="delete">
        <legend>Delete Brand</legend>
        <div>
        <label for="categoryid">Category:<br />
        <?php
            $stmt = $db->prepare("SELECT categoryid, category FROM categories");
            $stmt->execute();
            echo "<select name='categoryid' onchange='this.form.submit()'>";
            while ($row = $stmt->fetch(PDO::FETCH_ASSOC)) {
                echo "<option value='{$row['categoryid']}'>{$row['category']}</option>";
            }
            echo "</select>";
        ?>
        </label>
        </div>
        <div>
        <label for="brand">Brand Name:<br />
        <?php

            $stmt = $db->prepare("SELECT brands.id, brand FROM brands WHERE brands.categoryid = ")
        ?>
        </label>
        </div>
        <div>
        <input type="submit" value="Delete Brand" />
        </div>
        </fieldset>
        </form>

I’m still missing the last dropdown, but if I just can get the value from the selected item from the first dropdown, into a variable, it shouldn’t be hard for the rest of the code!

Thank you a lot

Answer 1

The below code is an example of how you can get the selected option value for a dropdown box. Depending on your needs, you can either preload your category id->brand mappings into a javascript variable that you can refer to, or use an ajax request to get the appropriate brands for your second combo box on demand, when the box is clicked.

<script>
function getSelected(obj)
{
    alert(obj.options[obj.selectedIndex].value);

    // Now use AJAX or preloaded variable to figure out 
    // what brands map to this category, and populate
    // your second combobox
}
</script>

<form action="deleteBrand.php" method="post">
<label for="categoryid">Category:<br />
<select name='categoryid' onchange=getSelected(this)>
<option value="1">A</option>
<option value="2">B</option>
<option value="3">C</option>
</select>
</form>