单表备份
代码：
代码如下:
<?php
class Db
{
var $conn;
function Db($host="localhost",$user="root",$pass="root",$db="test")
{
if(!$this->conn=mysql_connect($host,$user,$pass))
die("can't connect to mysql sever");
mysql_select_db($db,$this->conn);
mysql_query("SET NAMES 'UTF-8'");
}
function execute($sql)
{
return mysql_query($sql,$this->conn);
}
function findCount($sql)
{
$result=$this->execute($sql);
return mysql_num_rows($result);
}
function findBySql($sql)
{
$array=array();
$result=mysql_query($sql);
$i=0;
while($row=mysql_fetch_assoc($result))
{
$array[$i]=$row;
$i++;
}
return $array;
}
//$con的几种情况
//空：返回全部记录
//array：eg. array('id'=>'1') 返回id=1的记录
//string :eg. 'id=1' 返回id=1的记录
function toExtJson($table,$start="0",$limit="10",$cons="")
{
$sql=$this->generateSql($table,$cons);
$totalNum=$this->findCount($sql);
$result=$this->findBySql($sql." LIMIT ".$start." ,".$limit);
$resultNum = count($result);//当前结果数
