Mysqli & the Fuel backup module

Gumster · April 2015

I've just realised that CI's dbutil class isn't compatible with the mysqli driver, which in turn makes the Backup module ineffective.

Is there a workaround? I thought of using parallel db configs where everything but the backup module use mysqli but even so I get deprecation messages from PHP about using the mysql driver. Even if this worked, I'm not sure if it's a valid solution.

admin · April 2015

What errors are you seeing from the CI dbutil class and what version of PHP are you running?

Gumster · April 2015

I first noticed this trying to use a backup cron, but if you use the "Yes, back it up" button to download a zip, the same problem occurs.

I've got live and dev environments and both use mysqli. However, the live DB, I've only just noticed, is Percona 5.6.17-66.0 (a MySQL drop-in), but the dev server uses vanilla MySQL 5.6.17 with WAMP

#1 Live (Linux, PHP 5.4.37) error is:


A Database Error Occurred

Unsupported feature of the database platform you are using.

Filename: /.../fuel/modules/backup/libraries/Fuel_backup.php

Line Number: 512

#2 Dev (WAMP, PHP 5.5.12) error:


A Database Error Occurred

Unsupported feature of the database platform you are using.

Filename: \...\fuel\codeigniter\database\drivers\mysqli\mysqli_utility.php

Line Number: 82

..and I've just tried it on a Mac dev environment with MySQL 5.6.20 (mysqli), PHP 5.5.20 and it gives the same error as #1

I've noticed the backup mod didn't work on another (LAMP) site using MySQL 5.5.42, PHP 5.4.32, again using mysqli.

However, using the mysql connector it's OK.

admin · April 2015

There seems to be a few stackoverflows out there about this issue (I hadn't heard of it before):
http://stackoverflow.com/questions/24197844/database-utility-backups-not-working-with-mysqli-codeignitor
http://stackoverflow.com/questions/27116299/how-to-extend-the-codeigniter-database-utility-class

The accepted solution in the last link may be worth trying by perhaps extending the DB_utility class as a fuel/application/libraries/MY_DB_utility and replacing the following method:

public function dbutil()
{
    /* snip for brevity */
    $class = config_item('subclass_prefix').'DB_'.$db->dbdriver.'_utility';
    $filename = APPPATH.'libraries/'.$class.EXT;
    require_once($filename);
    /* snip for brevity */
 }

I haven't tested this yet and hope that you can simply extend it that way like most of the other CI classes.

Gumster · April 2015

I followed some of what went on in those articles, overriding dbutil() in MY_Loader, including the require of MY_DB_mysqli_utility (in application/libraries), and then I ripped the _backup() method from CI 3's mysqli_utility.php, made a few nip & tucks (replacing escape_identifiers() with _escape_identifiers() for example) and... amazingly I can export a zip of the sql from the backup module.

Gumster · April 2015

MY_DB_mysqli_utility.php added to /application/libraries:



class MY_DB_mysqli_utility extends CI_DB_utility {

    function __construct() {
        parent::__construct();
        log_message('debug', 'Extended DB mysqli utility class instantiated!');
    }

    /**
     * List databases
     *
     * @access	private
     * @return	bool
     */
    function _list_databases() {
        return "SHOW DATABASES";
    }

    // --------------------------------------------------------------------

    /**
     * Optimize table query
     *
     * Generates a platform-specific query so that a table can be optimized
     *
     * @access	private
     * @param	string	the table name
     * @return	object
     */
    function _optimize_table($table) {
        return "OPTIMIZE TABLE " . $this->db->_escape_identifiers($table);
    }

    // --------------------------------------------------------------------

    /**
     * Repair table query
     *
     * Generates a platform-specific query so that a table can be repaired
     *
     * @access	private
     * @param	string	the table name
     * @return	object
     */
    function _repair_table($table) {
        return "REPAIR TABLE " . $this->db->_escape_identifiers($table);
    }

    /**
     * Backup
     *
     * @param	array	$params	Preferences
     * @return	mixed
     */
    function _backup($params = array()) {

        if (count($params) === 0) {
            return FALSE;
        }
        // Extract the prefs for simplicity
        extract($params);
        // Build the output
        $output = '';

        foreach ((array) $tables as $table) {
            // Is the table in the "ignore" list?
            if (in_array($table, (array) $ignore, TRUE)) {
                continue;
            }
            // Get the table schema
            $query = $this->db->query('SHOW CREATE TABLE ' . $this->db->_escape_identifiers($this->db->database . '.' . $table));
            // No result means the table name was invalid
            if ($query === FALSE) {
                continue;
            }
            // Write out the table schema
            $output .= '#' . $newline . '# TABLE STRUCTURE FOR: ' . $table . $newline . '#' . $newline . $newline;
            if ($add_drop === TRUE) {
                $output .= 'DROP TABLE IF EXISTS ' . $this->db->_protect_identifiers($table) . ';' . $newline . $newline;
            }
            $i = 0;
            $result = $query->result_array();
            foreach ($result[0] as $val) {
                if ($i++ % 2) {
                    $output .= $val . ';' . $newline . $newline;
                }
            }
            // If inserts are not needed we're done...
            if ($add_insert === FALSE) {
                continue;
            }
            // Grab all the data from the current table
            $query = $this->db->query('SELECT * FROM ' . $this->db->_protect_identifiers($table));
            if ($query->num_rows() === 0) {
                continue;
            }
            // Fetch the field names and determine if the field is an
            // integer type. We use this info to decide whether to
            // surround the data with quotes or not
            $i = 0;
            $field_str = '';
            $is_int = array();
            while ($field = $query->result_id->fetch_field()) {
                // Most versions of MySQL store timestamp as a string
                $is_int[$i] = in_array(strtolower($field->type), array('tinyint', 'smallint', 'mediumint', 'int', 'bigint'), //, 'timestamp'),
                        TRUE);
                // Create a string of field names
                $field_str .= $this->db->_escape_identifiers($field->name) . ', ';
                $i++;
            }
            // Trim off the end comma
            $field_str = preg_replace('/, $/', '', $field_str);
            // Build the insert string
            foreach ($query->result_array() as $row) {
                $val_str = '';
                $i = 0;
                foreach ($row as $v) {
                    // Is the value NULL?
                    if ($v === NULL) {
                        $val_str .= 'NULL';
                    } else {
                        // Escape the data if it's not an integer
                        $val_str .= ($is_int[$i] === FALSE) ? $this->db->escape($v) : $v;
                    }
                    // Append a comma
                    $val_str .= ', ';
                    $i++;
                }
                // Remove the comma at the end of the string
                $val_str = preg_replace('/, $/', '', $val_str);
                // Build the INSERT string
                $output .= 'INSERT INTO ' . $this->db->_protect_identifiers($table) . ' (' . $field_str . ') VALUES (' . $val_str . ');' . $newline;
            }
            $output .= $newline . $newline;
        }

        return $output;
    }

}

Gumster · April 2015

MY_Loader amended to load the above class:



/* load the MX_Loader class */
require FUEL_PATH."core/Loader.php";

class MY_Loader extends Fuel_Loader {
    
    public function dbutil()
    {

        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();

    }

    
}

admin · April 2015

Awesome... I've tested it out as well and seems to do the trick. I'll post a change for the next release.

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Mysqli & the Fuel backup module

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