在codeigniter中自动加载数据库

Question

I am using this class:

<?php
class Decrypt extends CI_Controller
{



    public function decrypt1($toDescrypt="")
    {
        $this->load->library('encrypt');
        $toDescrypt = urldecode($toDescrypt);
        $s=unserialize($this->encrypt->decode($toDescrypt));
        echo $s["username"];
    }
}
?>

And I am using auto load feature for database. My config file:

$autoload['libraries'] = array('database','session');

But you can see I am not using database in decrypt1 method. Will codeigniter connect to database even i don't use the database operation?

Answer 1

This is a portion of CI DB_Driver class:

/**
 * Simple Query
 * This is a simplified version of the query() function.  Internally
 * we only use it when running transaction commands since they do
 * not require all the features of the main query() function.
 *
 * @access  public
 * @param   string  the sql query
 * @return  mixed
 */
function simple_query($sql)
{
    if ( ! $this->conn_id)
    {
        $this->initialize();
    }

    return $this->_execute($sql);
}

As you can see, database driver isn't loaded (and thus connected to db server) until the first query (DB_Driver::query() behaves almost same).

Another point, if somewhere earlier in the code you performed some db queries (like, checking user session/activity), then connection to db server is already established, even if you don't perform any queries to db in your's decrypt1() method.

Upd. Make sure to use lazy-loading in database config (autoinit option should be false).