<?php/*** mysql讀寫分離*/class db{  public function __construct($sql){    $chestr = strtolower(trim($sql));    //判斷sql語句有select關鍵字的話，就連接讀的數據庫,否則就連接寫數據庫    if(substr($chestr,0,6)=='select')    {      echo 'I am using slave db..<br>';      $link = mysql_connect("192.168.20.201:3306", "open", "123456") or die("Could not connect: " . mysql_error());      mysql_select_db("hadoop");      $result = mysql_query($sql);      while($row = mysql_fetch_array($result,MYSQL_ASSOC)){        $data[]=$row;      }      //print_r($data);exit;      echo mysql_get_host_info($link).mysql_get_server_info($link).mysql_get_proto_info($link).mysql_get_client_info().'<br>';    }else{      echo 'I am using master db..<br>';      $link = mysql_connect("192.168.20.195:3306","open","123456") or die("Could not connect: " . mysql_error());      mysql_select_db("hadoop");      $result = mysql_query($sql);      //echo @mysql_affected_rows($result);      echo mysql_get_host_info($link).mysql_get_server_info($link).mysql_get_proto_info($link).mysql_get_client_info().'<br>';    }  }}$master = new db("INSERT INTO user (id,name)VALUES (NULL,'100')");$slave = new db("SELECT * from `user`");