You’d like to take advantage of CodeIgniter’s built-in database backup function as described here…
http://www.codeigniter.com/user_guide/database/utilities.html#backup
As you can see, only the `mysql` PHP database extension is supported. However, since the `mysql` PHP database extension has been deprecated, maybe you’re using another PHP database extension like `mysqli` instead. Now the problem is that you can no longer use CodeIgniter’s built-in database backup function without getting this error…
Unsupported feature of the database platform you are using.
The error simply means that if you use any PHP database extension besides `mysql`, there is no function included within any of CodeIgniter’s database drivers’ utility file for doing the backup.
No problem, we’ll just “extend” CodeIgniter’s database class.
Wrong! As per documentation,
Note: The Database classes can not be extended or replaced with your own classes.
Despite this limitation, there is a workaround below that will not involve editing CodeIgniter’s core system files.
Solution:
Instead, we’ll simply “extend” CodeIgniter’s Loader class. Within this custom Loader, we’ll only copy and slightly modify the `dbutil()` function. Study the function below and compare it to the original. I simply check for the existence of my custom utility driver file and load it in place of the default.
`application/core/MY_Loader.php` contains…
<?php class MY_Loader extends CI_Loader {
public function dbutil()
{
// this function taken from CI v2.2.0
// system/core/Loader.php
// modified as indicated below
if (! class_exists('CI_DB'))
{
$this->database();
}
$CI =& get_instance();
// for backwards compatibility, load dbforge so we can extend dbutils off it
// this use is deprecated and strongly discouraged
$CI->load->dbforge();
require_once(BASEPATH . 'database/DB_utility.php');
// START custom >>
// path of default db utility file
$default_utility = BASEPATH . 'database/drivers/' . $CI->db->dbdriver . '/' . $CI->db->dbdriver . '_utility.php';
// path of my custom db utility file
$my_utility = APPPATH . 'libraries/MY_DB_' . $CI->db->dbdriver . '_utility.php';
// set custom db utility file if it exists
if (file_exists($my_utility))
{
$utility = $my_utility;
$extend = 'MY_DB_';
}
else
{
$utility = $default_utility;
$extend = 'CI_DB_';
}
// load db utility file
require_once($utility);
// set the class
$class = $extend . $CI->db->dbdriver . '_utility';
// << END custom
$CI->dbutil = new $class();
}
}
Now we need to find the database driver that we’re using. For `mysqli`, it should be located within `system/database/drivers/mysqli/mysqli_utility.php`. This file contains the `_backup()` function and you can see that it’s empty (“unsupported”).
Create an exact duplicate of this file; rename it `MY_DB_mysqli_utility.php` and place it here…
`application/libraries/MY_DB_mysqli_utility.php`
Everything within this file should remain the same as the original, except for the name of the `class` and the contents of the `_backup()` function…
<?php
class MY_DB_mysqli_utility extends CI_DB_utility {
// this code taken from CI v2.2.0
// system/database/drivers/mysqli/mysqli_utility.php
// everything in here is same as default mysqli_utility
....
// EXCEPT the _backup() function contains my own code
function _backup($params = array())
{
// my custom working backup code
....
NOW you can put whatever code you see fit into this version of the `_backup()` function. I’m not going to tell you how to do this, but you could look inside of `system/database/drivers/mysql/mysql_utility.php` for some inspiration. You could also try the backup function suggested in this posting, which seems to be working.
The advantages to my technique are as follows…
– Updating the CodeIgniter system files leaves this solution intact.
– Changing the `dbdriver` setting in `config/database.php` will simply cause a fallback to the selected database utility driver. This solution is specific to one particular database driver (`mysqli`).
– Removing the `MY_Loader.php` file causes a fallback to the default database utility driver.
– Removing the `MY_DB_mysqli_utility.php` file causes a fallback to the default database utility driver.
– Update any other database utility driver by changing `mysqli` where-ever appropriate.
Note: This solution was successfully performed using CodeIgniter v2.2.0.