Codeigniter使用外部文件替换database.php

I have two web sites using codeigniter that uses the same database configurations(hostname,username,password), just want to ask if the database configuration can be called from a external file? The thing is if i want to change my database root password i have to change the two sites database.php manually, now lets says i have 10 websites this will be a difficult task correct? i just want to change a single file so all sites can use that configuration.

I am using mysql via PHPmyadmin.

$db['default'] = array(
    'dsn'   => '',
    'hostname' => 'localhost',
    'username' => 'root',
    'password' => 'root',
    'database' => 'MyBlog',
    'dbdriver' => 'mysqli',

If you have need to use one configuration for all sites, you can make the file (i.e. db_config.php) and set ti somewhere to be available to all CI applications.

db_config.php

<?php

return [
    'dsn'   => '',
    'hostname' => 'localhost',
    'username' => '',
    'password' => '',
    'database' => '',
    'dbdriver' => 'mysqli',
    'dbprefix' => '',
    'pconnect' => FALSE,
    'db_debug' => (ENVIRONMENT !== 'production'),
    'cache_on' => FALSE,
    'cachedir' => '',
    'char_set' => 'utf8',
    'dbcollat' => 'utf8_general_ci',
    'swap_pre' => '',
    'encrypt' => FALSE,
    'compress' => FALSE,
    'stricton' => FALSE,
    'failover' => array(),
    'save_queries' => TRUE
];

Then in your APPPATH.'config/db.php' of every application you should have:

$db['default'] = require('/path/to/db_config.php');