Getting values into dropdown from DB - codeigniter

Question

I want to use my db values of table (Category) into a product/add form, but not able to get the values.
Model :
function getAllCategories()
{
$query = $this->db->get('category');
return $query->result_array();
}
Controller:
function getAllCategories()
{
$data['groups'] = $this->productmodel->getAllCategories();
$this->load->view('admin/product/add',$data);
}
View:
<div class="form-group">
<label for="exampleInputEmail1">Brand </label>
<select class="form-control">
<?php
$i = 0;
while($i < count($groups)){
$val= $groups[$i]['value'];
$des = $groups[$i]['category_name'];
echo "<option value='$i'>$des</option>";
}?>
</select>
</div>
Help me please it is urgent.I took reference from stack overflow only, but was not able to do it.

Answer 1

Use foreach loop for array data type
<select class="form-control">
<?php
foreach($groups as $group)
{
$val= $group['value'];
$des = $group['category_name'];
echo "<option value='$val'>$des</option>";
} ?>
</select>

Answer 2

Himanshu, Simply replace your code with this one in your view.
The thing is that you are not incrementing the value of $i
<div class="form-group">
<label for="exampleInputEmail1">Brand </label>
<select class="form-control">
<?php
$i = 0;
while ($i < count($groups)) {
$val = $groups[$i]['value'];
$des = $groups[$i]['category_name'];
echo "<option value='".$i."'>$des</option>";
$i++;
} ?>
</select>
</div>

Answer 3

No panic it's should be easy. Do you get some data from model in controller ?
First, var_dump this line $this->productmodel->getAllCategories();
Second, I think you should do $i++ in your while cycle
Like this
<?php
$i = 0;
while($i < count($groups)){
$val= $groups[$i]['value'];
$des = $groups[$i]['category_name'];
echo "<option value='$i'>$des</option>";
$i++;
}?>