主要特性
简单的读写分离
一个主数据库可以添加更多的只读数据库
读写分离但不用担心某些特性不支持
缺点同时连接两个数据库
英文比较烂也写几个字吧
php code for mysql read/write split
feature:
simply rw split
one mastercan add more slaves
support all mysql feature
link to the master and slave at the same time
PHP代码
mysql_rw_phpclassphp
<?php
/****************************************
*** mysqlrwphp version @
*** code by hqlulu#gmailcom
*** http://wwwaslibracom
*** http://codegooglecom/p/mysqlrwphp/
*** code modify from class_mysqlphp (uchome)
****************************************/
class mysql_rw_php {
//查询个数
var $querynum = ;
//当前操作的数据库连接
var $link = null;
//字符集
var $charset;
//当前数据库
var $cur_db = ;
//是否存在有效的只读数据库连接
var $ro_exist = false;
//只读数据库连接
var $link_ro = null;
//读写数据库连接
var $link_rw = null;
function mysql_rw_php(){
}
function connect($dbhost $dbuser $dbpw $dbname = $pconnect = $halt = TRUE) {
if($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 && $this>halt(Can not connect to MySQL server);
}
}
//只读连接失败
if(!$this>link && !$halt) return false;
//未初始化rw时第一个连接作为rw
if($this>link_rw == null)
$this>link_rw = $this>link;
if($this>version() > ) {
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() > ) {
@mysql_query(SET sql_mode= $this>link);
}
}
if($dbname) {
$this>select_db($dbname);
}
}
//连接一个只读的mysql数据库
function connect_ro($dbhost $dbuser $dbpw $dbname = $pconnect = ){
if($this>link_rw == null)
$this>link_rw = $this>link;
$this>link = null;
//不产生halt错误
$this>connect($dbhost $dbuser $dbpw $dbname $pconnect false);
if($this>link){
//连接成功
//echo link ro sussess!<br>;
$this>ro_exist = true;
$this>link_ro = $this>link;
if($this>cur_db){
//如果已经选择过数据库则需要操作一次
@mysql_select_db($this>cur_db $this>link_ro);
}
}else{
//连接失败
//echo link ro failed!<br>;
$this>link = &$this>link_rw;
}
}
//设置一系列只读数据库并且连接其中一个
function set_ro_list($ro_list){
if(is_array($ro_list)){
//随机选择其中一个
$link_ro = $ro_list[array_rand($ro_list)];
$this>connect_ro($link_ro[dbhost] $link_ro[dbuser] $link_ro[dbpw]);
}
}
function select_db($dbname) {
//同时操作两个数据库连接
$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;
//判断是否select语句
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)) >= ? $id : $this>result($this>query(SELECT last_insert_id()) );
}
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;fontsize:px;fontfamily:verdanaarial;background:#EBEBEB;padding:em;\>
<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();
}
}
?>
examplephp
<?php
/****************************************
*** mysqlrwphp version @
*** code by hqlulu#gmailcom
*** http://wwwaslibracom
*** http://codegooglecom/p/mysqlrwphp/
*** code modify from class_mysqlphp (uchome)
****************************************/
require_once(mysql_rw_phpclassphp);
//rw info
$db_rw = array(
dbhost=>wwwaslibracom
dbuser=>aslibra
dbpw=>wwwaslibracom
dbname=>test
);
$db_ro = array(
array(
dbhost=>wwwaslibracom:
dbuser=>aslibra
dbpw=>wwwaslibracom
)
);
$DB = new mysql_rw_php;
//connect Master
$DB>connect($db_rw[dbhost] $db_rw[dbuser] $db_rw[dbpw] $db_rw[dbname]);
//Method : connect one server
$DB>connect_ro($db_ro[][dbhost] $db_ro[][dbuser] $db_ro[][dbpw]);
//Method : 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];
}
?>
