先说下关于数据库备份与恢复的原理：
1、查找所有表->2、查找所有字段->3、查找所有数据->4、生成SQL
备份注意点：
2=>需要列出所有字段名，字段类型等相关信息
3=>读取数据出来注意特殊符号的转换addslashes()
4=>把数据格式化生成对应的SQL
mysql_list_tables() 表查询函数，类似mysql_query() 函数 mysql_fetch_field() 字段信息函数，返回句柄 恢复注意点： 1、 注意数据库的大小，过大或者过多的表分段处理
2、 生成的SQL文件名或者存放不易被猜到
3、 备份生成文件可以表或者字段为单位保存
4、可以使用ZIP组件压缩生成的文件以便保持 迷你版代码：
<?php
$mysql_dbname = "php100";
mysql_connect("localhost", "root", "");
mysql_select_db($mysql_dbname);
$sql_list = mysql_list_tables($mysql_dbname);
while ($row_data = mysql_fetch_row($sql_list)) {
echo $row_data[0] . "<br>";
get_table_fd($row_data[0], "sql");
// $fp=fopen("sql/$tablename.sql","w+");
// fwrite($fp,$field);
// fclose($fp);
}
function get_table_fd($tablename) {
$field = "CREATE TABLE `$tablename`(\n";
$result = mysql_query("select * from $tablename");
while ($meta = mysql_fetch_field($result)) {
if ($meta->not_null)
$not_null = "not_null";
$field .= "`$meta->name` $meta->type($meta->max_length) $not_null; \n";
}
$field .= ")\n";
return $field;
}
?>
在网上找到个不错的类库，可直接拿来用，记录一下
1、db.php 数据库类
2、backup.php 备份
3、restore.php 恢复
db.php
<?
class db{
var $linkid;
var $sqlid;
var $record;
function db($host="",$username="",$password="",$database="")
{
if(!$this->linkid) @$this->linkid = mysql_connect($host, $username, $password) or die("连接服务器失败.");
@mysql_select_db($database,$this->linkid) or die("无法打开数据库");
mysql_query('set names gbk');
return $this->linkid;}
function query($sql)
{if($this->sqlid=mysql_query($sql,$this->linkid)) return $this->sqlid;
else {
$this->err_report($sql,mysql_error);
return false;}
}
function nr($sql_id="")
{if(!$sql_id) $sql_id=$this->sqlid;
return mysql_num_rows($sql_id);}
function nf($sql_id="")
{if(!$sql_id) $sql_id=$this->sqlid;
return mysql_num_fields($sql_id);}
function nextrecord($sql_id="")
{if(!$sql_id) $sql_id=$this->sqlid;
if($this->record=mysql_fetch_array($sql_id)) return $this->record;
else return false;
}
function f($name)
{
if($this->record[$name]) return $this->record[$name];
else return false;
}
function close() {mysql_close($this->linkid);}
function lock($tblname,$op="WRITE")
{if(mysql_query("lock tables ".$tblname." ".$op)) return true; else return false;}
function unlock()
{if(mysql_query("unlock tables")) return true; else return false;}
function ar() {
return @mysql_affected_rows($this->linkid);
}
function i_id() {
return mysql_insert_id();
}
function err_report($sql,$err)
{
echo "Mysql查询错误<br>";
echo "查询语句：".$sql."<br>";
echo "错误信息：".$err;
}
}?>
backup.php
<?
global $mysqlhost, $mysqluser, $mysqlpwd, $mysqldb;
$mysqlhost=""; //host name
$mysqluser=""; //login name
$mysqlpwd=""; //password
$mysqldb=""; //name of database
include("mydb.php");
$d=new db($mysqlhost,$mysqluser,$mysqlpwd,$mysqldb);
/*--------------界面--------------*/if(!$_POST['act']){/*----------------------*/
$msgs[]="服务器备份目录为backup";
$msgs[]="对于较大的数据表，强烈建议使用分卷备份";
$msgs[]="只有选择备份到服务器，才能使用分卷备份功能";
show_msg($msgs);
?>
<form name="form1" method="post" action="backup.php">
<table width="99%" border="1" cellpadding='0' cellspacing='1'>
<tr align="center" class='header'><td colspan="2">数据备份</td></tr>
<tr><td colspan="2">备份方式</td></tr>
<tr><td><input type="radio" name="bfzl" value="quanbubiao"> 备份全部数据</td><td>备份全部数据表中的数据到一个备份文件</td></tr>
<tr><td><input type="radio" name="bfzl" value="danbiao">备份单张表数据
<select name="tablename"><option value="">请选择</option>
<?
$d->query("show table status from $mysqldb");
while($d->nextrecord()){
echo "<option value='".$d->f('Name')."'>".$d->f('Name')."</option>";}
?>
</select></td><td>备份选中数据表中的数据到单独的备份文件</td></tr>
<tr><td colspan="2">使用分卷备份</td></tr>
<tr><td colspan="2"><input type="checkbox" name="fenjuan" value="yes">
分卷备份 <input name="filesize" type="text" size="10">K</td></tr>
<tr><td colspan="2">选择目标位置</td></tr>
<tr><td colspan="2"><input type="radio" name="weizhi" value="server" checked>备份到服务器</td></tr><tr class="cells"><td colspan='2'> <input type="radio" name="weizhi" value="localpc">
备份到本地</td></tr>
<tr><td colspan="2" align='center'><input type="submit" name="act" value="备份"></td></tr>
</table></form>
<?/*-------------界面结束-------------*/}/*---------------------------------*/
/*----*/else{/*--------------主程序-----------------------------------------*/
if($_POST['weizhi']=="localpc"&&$_POST['fenjuan']=='yes')
{$msgs[]="只有选择备份到服务器，才能使用分卷备份功能";
show_msg($msgs); pageend();}
if($_POST['fenjuan']=="yes"&&!$_POST['filesize'])
{$msgs[]="您选择了分卷备份功能，但未填写分卷文件大小";
show_msg($msgs); pageend();}
if($_POST['weizhi']=="server"&&!writeable("./backup"))
{$msgs[]="备份文件存放目录'./backup'不可写，请修改目录属性";
show_msg($msgs); pageend();}
/*----------备份全部表-------------*/if($_POST['bfzl']=="quanbubiao"){/*----*/
/*----不分卷*/if(!$_POST['fenjuan']){/*--------------------------------*/
if(!$tables=$d->query("show table status from $mysqldb"))
{$msgs[]="读数据库结构错误"; show_msg($msgs); pageend();}
$sql="";
while($d->nextrecord($tables))
{
$table=$d->f("Name");
$sql.=make_header($table);
$d->query("select * from $table");
$num_fields=$d->nf();
while($d->nextrecord())
{$sql.=make_record($table,$num_fields);}
}
$filename=date("Ymd",time())."_all.sql";
if($_POST['weizhi']=="localpc") down_file($sql,$filename);
elseif($_POST['weizhi']=="server")
{if(write_file($sql,$filename))
$msgs[]="全部数据表数据备份完成,生成备份文件'./backup/$filename'";
else $msgs[]="备份全部数据表失败";
show_msg($msgs);
pageend();
}
/*-----------------不要卷结束*/}/*-----------------------*/
/*-----------------分卷*/else{/*-------------------------*/
if(!$_POST['filesize'])
{$msgs[]="请填写备份文件分卷大小"; show_msg($msgs);pageend();}
if(!$tables=$d->query("show table status from $mysqldb"))
{$msgs[]="读数据库结构错误"; show_msg($msgs); pageend();}
$sql=""; $p=1;
$filename=date("Ymd",time())."_all";
while($d->nextrecord($tables))
{
$table=$d->f("Name");
$sql.=make_header($table);
$d->query("select * from $table");
$num_fields=$d->nf();
while($d->nextrecord())
{$sql.=make_record($table,$num_fields);
if(strlen($sql)>=$_POST['filesize']*1000){
$filename.=("_v".$p.".sql");
if(write_file($sql,$filename))
$msgs[]="全部数据表-卷-".$p."-数据备份完成,生成备份文件'./backup/$filename'";
else $msgs[]="备份表-".$_POST['tablename']."-失败";
$p++;
$filename=date("Ymd",time())."_all";
$sql="";}
}
}
if($sql!=""){$filename.=("_v".$p.".sql");
if(write_file($sql,$filename))
$msgs[]="全部数据表-卷-".$p."-数据备份完成,生成备份文件'./backup/$filename'";}
show_msg($msgs);
/*---------------------分卷结束*/}/*--------------------------------------*/
/*--------备份全部表结束*/}/*---------------------------------------------*/
/*--------备份单表------*/elseif($_POST['bfzl']=="danbiao"){/*------------*/
if(!$_POST['tablename'])
{$msgs[]="请选择要备份的数据表"; show_msg($msgs); pageend();}
/*--------不分卷*/if(!$_POST['fenjuan']){/*-------------------------------*/
$sql=make_header($_POST['tablename']);
$d->query("select * from ".$_POST['tablename']);
$num_fields=$d->nf();
while($d->nextrecord())
{$sql.=make_record($_POST['tablename'],$num_fields);}
$filename=date("Ymd",time())."_".$_POST['tablename'].".sql";
if($_POST['weizhi']=="localpc") down_file($sql,$filename);
elseif($_POST['weizhi']=="server")
{if(write_file($sql,$filename))
$msgs[]="表-".$_POST['tablename']."-数据备份完成,生成备份文件'./backup/$filename'";
else $msgs[]="备份表-".$_POST['tablename']."-失败";
show_msg($msgs);
pageend();
}
/*----------------不要卷结束*/}/*------------------------------------*/
/*----------------分卷*/else{/*--------------------------------------*/
if(!$_POST['filesize'])
{$msgs[]="请填写备份文件分卷大小"; show_msg($msgs);pageend();}
$sql=make_header($_POST['tablename']); $p=1;
$filename=date("Ymd",time())."_".$_POST['tablename'];
$d->query("select * from ".$_POST['tablename']);
$num_fields=$d->nf();
while ($d->nextrecord())
{
$sql.=make_record($_POST['tablename'],$num_fields);
if(strlen($sql)>=$_POST['filesize']*1000){
$filename.=("_v".$p.".sql");
if(write_file($sql,$filename))
$msgs[]="表-".$_POST['tablename']."-卷-".$p."-数据备份完成,生成备份文件'./backup/$filename'";
else $msgs[]="备份表-".$_POST['tablename']."-失败";
$p++;
$filename=date("Ymd",time())."_".$_POST['tablename'];
$sql="";}
}
if($sql!=""){$filename.=("_v".$p.".sql");
if(write_file($sql,$filename))
$msgs[]="表-".$_POST['tablename']."-卷-".$p."-数据备份完成,生成备份文件'./backup/$filename'";}
show_msg($msgs);
/*----------分卷结束*/}/*--------------------------------------------------*/
/*----------备份单表结束*/}/*----------------------------------------------*/
/*---*/}/*-------------主程序结束------------------------------------------*/
function write_file($sql,$filename)
{
$re=true;
if(!@$fp=fopen("./backup/".$filename,"w+")) {$re=false; echo "failed to open target file";}
if(!@fwrite($fp,$sql)) {$re=false; echo "failed to write file";}
if(!@fclose($fp)) {$re=false; echo "failed to close target file";}
return $re;
}
function down_file($sql,$filename)
{
ob_end_clean();
header("Content-Encoding: none");
header("Content-Type: ".(strpos($_SERVER['HTTP_USER_AGENT'], 'MSIE') ? 'application/octetstream' : 'application/octet-stream'));
header("Content-Disposition: ".(strpos($_SERVER['HTTP_USER_AGENT'], 'MSIE') ? 'inline; ' : 'attachment; ')."filename=".$filename);
header("Content-Length: ".strlen($sql));
header("Pragma: no-cache");
header("Expires: 0");
echo $sql;
$e=ob_get_contents();
ob_end_clean();
}
function writeable($dir)
{
if(!is_dir($dir)) {
@mkdir($dir, 0777);
}
if(is_dir($dir))
{
if($fp = @fopen("$dir/test.test", 'w'))
{
@fclose($fp);
@unlink("$dir/test.test");
$writeable = 1;
}
else {
$writeable = 0;
}
}
return $writeable;
}
function make_header($table)
{global $d;
$sql="DROP TABLE IF EXISTS ".$table."\n";
$d->query("show create table ".$table);
$d->nextrecord();
$tmp=preg_replace("/\n/","",$d->f("Create Table"));
$sql.=$tmp."\n";
return $sql;
}
function make_record($table,$num_fields)
{global $d;
$comma="";
$sql .= "INSERT INTO ".$table." VALUES(";
for($i = 0; $i < $num_fields; $i++)
{$sql .= ($comma."'".mysql_escape_string($d->record[$i])."'"); $comma = ",";}
$sql .= ")\n";
return $sql;
}
function show_msg($msgs)
{
$title="提示：";
echo "<table width='100%' border='1' cellpadding='0' cellspacing='1'>";
echo "<tr><td>".$title."</td></tr>";
echo "<tr><td><br><ul>";
while (list($k,$v)=each($msgs))
{
echo "<li>".$v."</li>";
}
echo "</ul></td></tr></table>";
}
function pageend()
{
exit();
}
?>
restore.php
<?
session_start();
global $mysqlhost, $mysqluser, $mysqlpwd, $mysqldb;
$mysqlhost=""; //host name
$mysqluser=""; //login name
$mysqlpwd=""; //password
$mysqldb=""; //name of database
include("mydb.php");
$d=new db($mysqlhost,$mysqluser,$mysqlpwd,$mysqldb);
/******界面*/if(!$_POST['act']&&!$_SESSION['data_file']){/**********************/
$msgs[]="本功能在恢复备份数据的同时，将全部覆盖原有数据，请确定是否需要恢复，以免造成数据损失";
$msgs[]="数据恢复功能只能恢复由dShop导出的数据文件，其他软件导出格式可能无法识别";
$msgs[]="从本地恢复数据需要服务器支持文件上传并保证数据尺寸小于允许上传的上限，否则只能使用从服务器恢复";
$msgs[]="如果您使用了分卷备份，只需手工导入文件卷1，其他数据文件会由系统自动导入";
show_msg($msgs);
?>
<form action="" method="post" enctype="multipart/form-data" name="restore.php">
<table width="91%" border="0" cellpadding="0" cellspacing="1">
<tr align="center" class="header"><td colspan="2" align="center">数据恢复</td></tr>
<tr><td width="33%"><input type="radio" name="restorefrom" value="server" checked>
从服务器文件恢复 </td><td width="67%"><select name="serverfile">
<option value="">-请选择-</option>
<?
$handle=opendir('./backup');
while ($file = readdir($handle)) {
if(eregi("^[0-9]{8,8}([0-9a-z_]+)(\.sql)$",$file)) echo "<option value='$file'>$file</option>";}
closedir($handle);
?>
</select> </td></tr>
<tr><td><input type="radio" name="restorefrom" value="localpc"> 从本地文件恢复</td>
<td><input type="hidden" name="MAX_FILE_SIZE" value="1500000"><input type="file" name="myfile"></td></tr>
<tr><td colspan="2" align="center"> <input type="submit" name="act" value="恢复"></td> </tr></table></form>
<?/**************************界面结束*/}/*************************************/
/****************************主程序*/if($_POST['act']=="恢复"){/**************/
/***************服务器恢复*/if($_POST['restorefrom']=="server"){/**************/
if(!$_POST['serverfile'])
{$msgs[]="您选择从服务器文件恢复备份，但没有指定备份文件";
show_msg($msgs); pageend(); }
if(!eregi("_v[0-9]+",$_POST['serverfile']))
{$filename="./backup/".$_POST['serverfile'];
if(import($filename)) $msgs[]="备份文件".$_POST['serverfile']."成功导入数据库";
else $msgs[]="备份文件".$_POST['serverfile']."导入失败";
show_msg($msgs); pageend();
}
else
{
$filename="./backup/".$_POST['serverfile'];
if(import($filename)) $msgs[]="备份文件".$_POST['serverfile']."成功导入数据库";
else {$msgs[]="备份文件".$_POST['serverfile']."导入失败";show_msg($msgs);pageend();}
$voltmp=explode("_v",$_POST['serverfile']);
$volname=$voltmp[0];
$volnum=explode(".sq",$voltmp[1]);
$volnum=intval($volnum[0])+1;
$tmpfile=$volname."_v".$volnum.".sql";
if(file_exists("./backup/".$tmpfile))
{
$msgs[]="程序将在3秒钟后自动开始导入此分卷备份的下一部份：文件".$tmpfile."，请勿手动中止程序的运行，以免数据库结构受损";
$_SESSION['data_file']=$tmpfile;
show_msg($msgs);
sleep(3);
echo "<script language='javascript'>";
echo "location='restore.php';";
echo "</script>";
}
else
{
$msgs[]="此分卷备份全部导入成功";
show_msg($msgs);
}
}
/**************服务器恢复结束*/}/********************************************/
/*****************本地恢复*/if($_POST['restorefrom']=="localpc"){/**************/
switch ($_FILES['myfile']['error'])
{
case 1:
case 2:
$msgs[]="您上传的文件大于服务器限定值，上传未成功";
break;
case 3:
$msgs[]="未能从本地完整上传备份文件";
break;
case 4:
$msgs[]="从本地上传备份文件失败";
break;
case 0:
break;
}
if($msgs){show_msg($msgs);pageend();}
$fname=date("Ymd",time())."_".sjs(5).".sql";
if (is_uploaded_file($_FILES['myfile']['tmp_name'])) {
copy($_FILES['myfile']['tmp_name'], "./backup/".$fname);}
if (file_exists("./backup/".$fname))
{
$msgs[]="本地备份文件上传成功";
if(import("./backup/".$fname)) {$msgs[]="本地备份文件成功导入数据库"; unlink("./backup/".$fname);}
else $msgs[]="本地备份文件导入数据库失败";
}
else ($msgs[]="从本地上传备份文件失败");
show_msg($msgs);
/****本地恢复结束*****/}/****************************************************/
/****************************主程序结束*/}/**********************************/
/*************************剩余分卷备份恢复**********************************/
if(!$_POST['act']&&$_SESSION['data_file'])
{
$filename="./backup/".$_SESSION['data_file'];
if(import($filename)) $msgs[]="备份文件".$_SESSION['data_file']."成功导入数据库";
else {$msgs[]="备份文件".$_SESSION['data_file']."导入失败";show_msg($msgs);pageend();}
$voltmp=explode("_v",$_SESSION['data_file']);
$volname=$voltmp[0];
$volnum=explode(".sq",$voltmp[1]);
$volnum=intval($volnum[0])+1;
$tmpfile=$volname."_v".$volnum.".sql";
if(file_exists("./backup/".$tmpfile))
{
$msgs[]="程序将在3秒钟后自动开始导入此分卷备份的下一部份：文件".$tmpfile."，请勿手动中止程序的运行，以免数据库结构受损";
$_SESSION['data_file']=$tmpfile;
show_msg($msgs);
sleep(3);
echo "<script language='javascript'>";
echo "location='restore.php';";
echo "</script>";
}
else
{
$msgs[]="此分卷备份全部导入成功";
unset($_SESSION['data_file']);
show_msg($msgs);
}
}
/**********************剩余分卷备份恢复结束*******************************/
function import($fname)
{global $d;
$sqls=file($fname);
foreach($sqls as $sql)
{
str_replace("\r","",$sql);
str_replace("\n","",$sql);
if(!$d->query(trim($sql))) return false;
}
return true;
}
function show_msg($msgs)
{
$title="提示：";
echo "<table width='100%' border='1' cellpadding='0' cellspacing='1'>";
echo "<tr><td>".$title."</td></tr>";
echo "<tr><td><br><ul>";
while (list($k,$v)=each($msgs))
{
echo "<li>".$v."</li>";
}
echo "</ul></td></tr></table>";
}
function pageend()
{
exit();
}
?>