本代碼是從uchome的代碼修改的，是因為要解決uchome的效率而處理的。封裝的方式比較簡單，增加了只讀數(shù)據(jù)庫連接的接口擴展，不使用只讀數(shù)據(jù)庫也不影響原代碼使用。有待以后不斷完善。。

為了方便，試試建立了google的一個項目：http://code.google.com/p/mysql-rw-php/

希望給有需要的朋友帶來幫助。

PHP實現(xiàn)的Mysql讀寫分離

主要特性：

簡單的讀寫分離一個主數(shù)據(jù)庫，可以添加更多的只讀數(shù)據(jù)庫讀寫分離但不用擔心某些特性不支持缺點：同時連接兩個數(shù)據(jù)庫英文比較爛，也寫幾個字吧

php code for mysql read/write splitfeature:simply rw splitone master,can add more slavessupport all mysql featurelink to the master and slave at the same time

PHP代碼：

mysql_rw_php.class.php

<?php/******************************************* mysql-rw-php version 0.1 @ 2009-4-16*** code by hqlulu#gmail.com*** http://www.aslibra.com*** http://code.google.com/p/mysql-rw-php/*** code modify from class_mysql.php (uchome)****************************************/class mysql_rw_php { //查詢個數(shù) var $querynum = 0; //當前操作的數(shù)據(jù)庫連接 var $link = null; //字符集 var $charset; //當前數(shù)據(jù)庫 var $cur_db = ”; //是否存在有效的只讀數(shù)據(jù)庫連接 var $ro_exist = false; //只讀數(shù)據(jù)庫連接 var $link_ro = null; //讀寫數(shù)據(jù)庫連接 var $link_rw = null; function mysql_rw_php(){ } function connect($dbhost, $dbuser, $dbpw, $dbname = ”, $pconnect = 0, $halt = TRUE) { if($pconnect) { if(!$this->link = @mysql_pconnect($dbhost, $dbuser, $dbpw)) { $halt && $this->halt(’Can not connect to MySQL server’); } } else { if(!$this->link = @mysql_connect($dbhost, $dbuser, $dbpw)) { $halt && $this->halt(’Can not connect to MySQL server’); } } //只讀連接失敗 if(!$this->link && !$halt) return false; //未初始化rw時，第一個連接作為rw if($this->link_rw == null) $this->link_rw = $this->link; if($this->version() > ‘4.1′) { if($this->charset) { @mysql_query(”SET character_set_connection=$this->charset, character_set_results=$this->charset, character_set_client=binary”, $this->link); } if($this->version() > ‘5.0.1′) { @mysql_query(”SET sql_mode=””, $this->link); } } if($dbname) { $this->select_db($dbname); } } //http://www.mypchelp.cn/php.asp 連接一個只讀的mysql數(shù)據(jù)庫 function connect_ro($dbhost, $dbuser, $dbpw, $dbname = ”, $pconnect = 0){ if($this->link_rw == null) $this->link_rw = $this->link; $this->link = null; //不產(chǎn)生halt錯誤 $this->connect($dbhost, $dbuser, $dbpw, $dbname, $pconnect, false); if($this->link){ //連接成功 //echo “l(fā)ink ro sussess!<br>”; $this->ro_exist = true; $this->link_ro = $this->link; if($this->cur_db){ //如果已經(jīng)選擇過數(shù)據(jù)庫則需要操作一次 @mysql_select_db($this->cur_db, $this->link_ro); } }else{ //連接失敗 //echo “l(fā)ink ro failed!<br>”; $this->link = &$this->link_rw; } } //設置一系列只讀數(shù)據(jù)庫并且連接其中一個 function set_ro_list($ro_list){ if(is_array($ro_list)){ //隨機選擇其中一個 $link_ro = $ro_list[array_rand($ro_list)]; $this->connect_ro($link_ro['dbhost'], $link_ro['dbuser'], $link_ro['dbpw']); } } function select_db($dbname) { //同時操作兩個數(shù)據(jù)庫連接 $this->cur_db = $dbname; if($this->ro_exist){ @mysql_select_db($dbname, $this->link_ro); } return @mysql_select_db($dbname, $this->link_rw); } function fetch_array($query, $result_type = MYSQL_ASSOC) { return mysql_fetch_array($query, $result_type); } function fetch_one_array($sql, $type = ”) { $qr = $this->query($sql, $type); return $this->fetch_array($qr); } function query($sql, $type = ”) { $this->link = &$this->link_rw; //判斷是否select語句 if($this->ro_exist && preg_match (”/^(s*)select/i”, $sql)){ $this->link = &$this->link_ro; } $func = $type == ‘UNBUFFERED’ && @function_exists(’mysql_unbuffered_query’) ? ‘mysql_unbuffered_query’ : ‘mysql_query’; if(!($query = $func($sql, $this->link)) && $type != ‘SILENT’) { $this->halt(’MySQL Query Error’, $sql); } $this->querynum++; return $query; } function affected_rows() { return mysql_affected_rows($this->link); } function error() { return (($this->link) ? mysql_error($this->link) : mysql_error()); } function errno() { return intval(($this->link) ? mysql_errno($this->link) : mysql_errno()); } function result($query, $row) { $query = @mysql_result($query, $row); return $query; } function num_rows($query) { $query = mysql_num_rows($query); return $query; } function num_fields($query) { return mysql_num_fields($query); } function free_result($query) { return mysql_free_result($query); } function insert_id() { return ($id = mysql_insert_id($this->link)) >= 0 ? $id : $this->result($this->query(”SELECT last_insert_id()”), 0); } function fetch_row($query) { $query = mysql_fetch_row($query); return $query; } function fetch_fields($query) { return mysql_fetch_field($query); } function version() { return mysql_get_server_info($this->link); } function close() { return mysql_close($this->link); } function halt($message = ”, $sql = ”) { $dberror = $this->error(); $dberrno = $this->errno(); echo “<div style=”position:absolute;font-size:11px;font-family:verdana,arial;background:#EBEBEB;padding:0.5em;”> <b>MySQL Error</b><br> <b>Message</b>: $message<br> <b>SQL</b>: $sql<br> <b>Error</b>: $dberror<br> <b>Errno.</b>: $dberrno<br> </div>”; exit(); }}?>example.php

<?php/******************************************* mysql-rw-php version 0.1 @ 2009-4-16*** code by hqlulu#gmail.com*** http://www.aslibra.com*** http://code.google.com/p/mysql-rw-php/*** code modify from class_mysql.php (uchome)****************************************/require_once(’mysql_rw_php.class.php’);//rw info$db_rw = array( ‘dbhost’=>’www.aslibra.com’, ‘dbuser’=>’aslibra’, ‘dbpw’=>’www.aslibra.com’, ‘dbname’=>’test’);$db_ro = array( array( ‘dbhost’=>’www.aslibra.com:4306′, ‘dbuser’=>’aslibra’, ‘dbpw’=>’www.aslibra.com’ ));$DB = new mysql_rw_php;//connect Master$DB->connect($db_rw[dbhost], $db_rw[dbuser], $db_rw[dbpw], $db_rw[dbname]);//Method 1: connect one server$DB->connect_ro($db_ro[0][dbhost], $db_ro[0][dbuser], $db_ro[0][dbpw]);//Method 2: connect one server from a list by rand$DB->set_ro_list($db_ro);//send to rw$sql = “insert into a set a=’test’”;$DB->query($sql);//send to ro$sql = “select * from a”;$qr = $DB->query($sql);while($row = $DB->fetch_array($qr)){ echo $row[a];}?>