Question

I am developing an API using Codeigniter and in this API the users can tag
themself. I need to display the 10 most popular tags (most frequestly used tags).
How can I do that?

Update

The tag table contains:

id, user_id, tag, created_at, updated_at

Answer 1

Jonathan, depending on your setup the solution will be different, I’m going to suggest something a bit different than what your table structure looks like, you can use it if you want to.

.--------------.    .-------------.
|   userTags   |    |     tags    |
.--------------.    .-------------.
|  id          |    | id          |
|  user_id     |    | tagName     |
|  tag_id      |    .-------------.
.--------------.

To add a tag to your database:
$data = array(‘tagName’ => ‘Mr. Niceguy’);
$this->db->insert(‘tags’ => $data);

To add a tag to your user, you could use the following in a model

$data = array('user_id' => $uId, 'tag_id' => 1);
$this->db->insert('userTags', $data);

To recieve the most common used tags:

$this->db->select('tag_id');
$this->db->order('tag_id DESC');
$this->db->limit(10);
$this->db->join('tags', 'userTags.tag_id = tags.id');
$this->db->get('userTags');

Edit:

If you have to use your setup, do this instead:

$this->db->order_by('count(tag)', 'DESC');
$this->db->group_by('tag', 'DESC');
$tags = $this->db->get('userTags');

foreach($tags->result() as $tag) {
    var_dump($tag->tag);
}