How to Retrieve the Last Auto-Incremented ID After an Insert Operation in CodeIgniter Active Record?

Getting the Last Auto-Incremented ID with CodeIgniter Active Record

Question:

You're trying to retrieve the last auto-incremented ID after performing an insert operation using CodeIgniter's Active Record, but the add_post() method in your model returns an empty value.

Inside the Controller:

<code class="php">function add_post(){
    $post_data = array(
        'id'            => '',
        'user_id'   =>  '11330',
        'content'   =>  $this->input->post('poster_textarea'),
        'date_time' => date("Y-m-d H:i:s"),
        'status'        =>  '1'
    );
    return $this->blog_model->add_post($post_data);
}</code>

Inside the Model:

<code class="php">function add_post($post_data){
    $this->db->trans_start();
    $this->db->insert('posts',$post_data);
    $this->db->trans_complete();
    return $this->db->insert_id();
}</code>

Answer:

The problem lies in the order of operations in your add_post() method in the model. To correctly retrieve the last auto-incremented ID after the insert operation, you need to:

1. Perform the insert operation first, using the $this->db->insert('posts', $post_data) method.
2. Then, retrieve the last inserted ID using the $this->db->insert_id() method.
3. Return the last inserted ID as the result of the add_post() method.

Solution:

<code class="php">function add_post($post_data){
    $this->db->insert('posts', $post_data);
    $insert_id = $this->db->insert_id();

    return $insert_id;
}</code>

Note:

If you're performing multiple inserts in a single transaction, you can use the $this->db->trans_start() and $this->db->trans_complete() methods to begin and end the transaction.

The above is the detailed content of How to Retrieve the Last Auto-Incremented ID After an Insert Operation in CodeIgniter Active Record?. For more information, please follow other related articles on the PHP Chinese website!