mysqldump.php

<?php

/*
* Database MySQLDump Class File
* Copyright (c) 2009 by James Elliott
* James.d.Elliott@gmail.com
* GNU General Public License v3 http://www.gnu.org/licenses/gpl.html
*
*/

class MySQLDump
{

    // This can be set both on counstruct or manually 
    public $host = 'localhost', $user = '', $pass = '', $db = '';
    public $filename = 'dump.sql';

    // Usable switch 
    public $droptableifexists = false;

    // Internal stuff
    private $tables = array();
    private $db_handler;
    private $file_handler;

    /**
     * Constructor of MySQLDump
     * 
     * @param string $db        Database name
     * @param string $user      MySQL account username
     * @param string $pass      MySQL account password
     * @param string $host      MySQL server to connect to
     * @return null
     */
    public function __construct($db = '', $user = '', $pass = '', $host = 'localhost')
    {
        $this->db = $db; $this->user = $user; $this->pass = $pass; $this->host = $host;
    }

    /**
     * Main call
     * 
     * @param string $filename  Name of file to write sql dump to     
     * @return bool
     */
    public function start($filename = '')
    {
        // Output file can be redefined here
        if(!empty($filename)) $this->filename = $filename;
        // We must set a name to continue
        if(empty($this->filename)) throw new Exception("Output file name is not set", 1);
        // Trying to bind a file with block
        $this->file_handler = fopen($this->filename, "wb");
        if($this->file_handler === FALSE) throw new Exception("Output file is not writable", 2);
        // Connecting with MySQL
        try {
            $this->db_handler = new PDO("mysql:dbname={$this->db};host={$this->host}", $this->user, $this->pass);
        } catch (PDOException $e) {
            throw new Exception("Connection to MySQL failed with message: ".$e->getMessage(), 3);
        }
        // Fix for always-unicode output 
        $this->db_handler->exec("SET NAMES utf8");      
        // https://github.com/clouddueling/mysqldump-php/issues/9
        $this->db_handler->setAttribute(PDO::ATTR_ORACLE_NULLS, PDO::NULL_NATURAL);
        // Formating dump file
        $this->write_header();
        // Listing all tables from database
        $this->tables = array();
        foreach ($this->db_handler->query("SHOW TABLES") as $row) {
            array_push($this->tables, current($row));
        }
        // Exporting tables one by one 
        foreach($this->tables as $table) {
            $this->write("-- --------------------------------------------------------\n\n");
            $this->get_table_structure($table);
            $this->list_values($table);
        }
        // Releasing file
        return fclose($this->file_handler);
    }
    
    /**
     * Output routine
     * 
     * @param string $string  SQL to write to dump file
     * @return bool
     */    
    private function write($string) {
        if(fwrite($this->file_handler, $string) === FALSE) {
            throw new Exception("Writting to file failed! Probably, there is no more free space left?", 4);
        }
    }

    /**
     * Writting header for dump file
     * 
     * @return null
     */   
    private function write_header()
    {
        // Some info about software, source and time
        $this->write("-- mysqldump-php SQL Dump\n");
        $this->write("-- https://github.com/clouddueling/mysqldump-php\n");
        $this->write("--\n");
        $this->write("-- Host: {$this->host}\n");
        $this->write("-- Generation Time: ".date('r')."\n\n");   
        $this->write("--\n");
        $this->write("-- Database: `{$this->db}`\n");
        $this->write("--\n\n");        
    }

    /**
     * Table structure extractor
     * 
     * @param string $tablename  Name of table to export
     * @return null
     */    
    private function get_table_structure($tablename)
    {
        $this->write( "--\n-- Table structure for table `$tablename`\n--\n\n" );
        if ($this->droptableifexists) {
           $this->write( "DROP TABLE IF EXISTS `$tablename`;\n\n" );
        }
        foreach ($this->db_handler->query("SHOW CREATE TABLE `$tablename`") as $row) {
           $this->write( $row['Create Table'].";\n\n" );
        }
    }

    /**
     * Table rows extractor
     * 
     * @param string $tablename  Name of table to export
     * @return null
     */   
    private function list_values($tablename)
    {
        $this->write("--\n-- Dumping data for table `$tablename`\n--\n\n");
        foreach ($this->db_handler->query("SELECT * FROM `$tablename`", PDO::FETCH_NUM) as $row) {
            $vals = array();
            foreach($row as $val) {
                $vals[] = is_null($val) ? "NULL" : $this->db_handler->quote($val);
            }
            $this->write("INSERT INTO `$tablename` VALUES(".implode(", ",$vals).");\n");
        }
        $this->write("\n");
    }
}

?>