php备份数据库

<?php

// 设置页面执行时间
set_time_limit(0);
// 设置内存无限制
ini_set('memory_limit', '-1');

class BackupMySQL {
    private $DB_HOST = '127.0.0.1'; // 数据库主机名
    private $DB_USER = 'root'; // 数据库用户名
    private $DB_PASS = 'pwd'; // 数据库密码
    private $DB_NAME = 'dbname'; // 数据库名

    // 备份文件保存路径
    private $backup_path = './backup/';

    function __construct($backup_path,$dbname){
        $this->backup_path = $backup_path;
        $this->DB_NAME = $dbname;
    }

    // 备份数据库
    function backup(){
        $mysqli = new mysqli($this->DB_HOST, $this->DB_USER, $this->DB_PASS, $this->DB_NAME);
        if(mysqli_connect_errno()){
            throw new Exception("Connect failed: ".mysqli_connect_error());
        }
        $mysqli->query("set names utf8");
        $tables = array();
        $result = $mysqli->query("show tables");
        while($row = $result->fetch_row()){
            $tables[] = $row[0];
        }
        $mysqli->query("SET FOREIGN_KEY_CHECKS=0");
        $sql = '';
        foreach($tables as $table){
            $result = $mysqli->query("select * from ".$table);
            $num_fileds = $result->field_count;
            $num_rows = $mysqli->affected_rows;
            $sql .= 'DROP TABLE IF EXISTS '.$table.';';
            $mysql_query = $mysqli->query('show create table '.$table);
            if (empty($mysql_query)) {
                continue;
            }
            $row2 = $mysql_query->fetch_row();
            $sql .= "\n\n".$row2[1].";\n\n";
            for($i = 0; $i < $num_rows; $i++){
                $row = $result->fetch_row();
                $sql .= "INSERT INTO ".$table." VALUES(";
                for($j = 0; $j < $num_fileds; $j++){
                    $row[$j] = addslashes($row[$j]);
                    $row[$j] = preg_replace("/\n/i","\\n",$row[$j]);
                    if(isset($row[$j])){
                        $sql .= '"'.$row[$j].'"';
                    }
                    else{
                        $sql.= '""';
                    }
                    if($j < ($num_fileds - 1)){
                        $sql .= ',';
                    }
                }
                $sql .= ");\n";
            }
            $sql .= "\n\n\n";
        }
        $mysqli->query("SET FOREIGN_KEY_CHECKS=1");
        $filename = $this->backup_path.$this->DB_NAME.".sql";
        mysqli_close($mysqli);
        if(file_put_contents($filename, $sql)){
            return true;
        }
        else{
            return false;
        }
    }
}

//查看所有的数据库信息
$mysqli = new mysqli('127.0.0.1', 'root', 'pwd', 'dbname');
if(mysqli_connect_errno()){
    throw new Exception("Connect failed: ".mysqli_connect_error());
}
$mysqli->query("set names utf8");
$databases = array();
$result = $mysqli->query("show databases");
while($row = $result->fetch_row()){
    $databases[] = $row[0];
}
//关闭数据库连接
mysqli_close($mysqli);

foreach ($databases as $key => $value) {
    $backup = new BackupMySQL('./backup/',$value);
    try {
        $backup->backup();
        echo $value.'数据库已备份=>';
    } catch (Exception $e) {
        echo '备份失败：'.$e->getMessage();
    }
}
echo "success";