php實作的支援讀寫分離的MySQL類

/**
* MySQL讀取與寫入分離類別
* $db_config = array(
* 'master' => array('host'=>'localhost:3306','user'=>'admin',' passwd'=>'123456','db'=>'stat'),
* 'slave' => array(
* array('host'=>'localhost:3307','user'= >'admin','passwd'=>'123456','db'=>'stat'),
* array('host'=>'localhost:3308','user'=>'admin', 'passwd'=>'123456','db'=>'stat')
* )
* );
*
* 註：如果slave有多個時隨機連接其中的一個
* 最後編輯：bbs.it-home.org
*/
/*
$db_config = array(
 'master' => array('host'=>'localhost:3306','user'=>'admin','passwd'=>'123456','db'=>' stat'),
 '從站' => array(
 array('host'=>'localhost:3307','user'=>'admin','passwd'=>'123456 ','db'=>'stat' ),
 array('host'=>'localhost:3308','user'=>'admin','passwd'=>'123456', 'db'=>'stat')
 )
);
$db = MySQL::getInstance('','r-w');< ;/p>
$sql = "從管理中選擇*";
$rs = $db->query($sql);
 while ($row = $db->fetch($rs)){
 echo "uid:".$row['uid']." ".$row['userName']."";
}

echo "
";
*/
class MySQL
{
 private static $_instance = null;//資料庫連線實例
 private static $_master = null;/ /主資料庫連線實例
 private static $_slave = null;//重新資料庫連線實例

 public $_config = array();//資料庫連線設定資訊
 public $_res = null; //查詢實例句柄
 public $_flag = '';//標識目前語句是在主或重資料庫上執行
 public $_link = null;

 /**
 * 單一實例
 * 在此輸入描述...
 * @paramknown_type $dbname
 * @paramunknown_type $mode
* /
 public static function & getInstance($dbname='',$mode='rw '){
 if (is_null(self::$_instance)){
 self::$_instance = new self ();
 self::$_instance->__getConf();
 self::$_instance->connect($dbname,$mode);
 }

 return self:: $_instance;
 }
 /**
 * 取得資料庫設定資訊
 * Enter description here ...
*/
 public function __getConf(){
 global $db_config;
 $this->_config[🎜> global $db_config;
 $this->_config[ 'master'] = $db_config['master'];
 $this->_config['slave'] = $db_config['slave'];
 }

 /**
 * 資料庫連線
 * Enter description here ...
 * @param $dbname 指定連接的資料庫名，預設連接設定檔的函式庫
 * @param $mode rw表示連接主庫，r-w表示讀寫分離
*/
 public function connect($dbname='' ,$mode = 'rw'){
 if($mode == 'rw'){
 if(is_null(self::$_master )){
 $this->_master = $this ->_slave = $this->conn_master($dbname);
 }
 }else{
 if(is_null(self::$_master )){
 $this->_master = $this->conn_master($dbname);
 }
 if(is_null(self::$_slave)){
 $this->_slave = $this->conn_slave($dbname );
 }
 }
 }

 /**
 * 連接到主資料庫伺服器
 * Enter description here ...
*/
 public function conn_master($dbname=''){
 $_link = mysql_connect( $this->_config['master']['host'],$this->_config['master']['user'],$this->_config['master'] ['passwd'] ,true) 或死亡("連線".$this->_config['master']['host']." 失敗。 ");
 mysql_select_db(empty($dbname)?$this->_config ['master']['db']:$dbname,$_link) 或die(" 資料庫名稱".$this->_config[ 'master']['db']." 不存在。") ;
 mysql_query("設定名稱utf8",$_link);
 return $_link; }

 /**
 * 連接到從資料庫伺服器
 * Enter description here ...
*/
 public function conn_slave($dbname=''){
 $offset = rand(0,count($this->_config['slave') ])-1);
 $_link = @mysql_connect($this->_config['slave'][$offset]['host'],$this->_config['slave'][$offset ][ 'user'],$this->_config['slave'][$offset]['passwd'],true) 或die(" Connect ".$this->_config['slave'][$offset][' host']." 失敗。");
 mysql_select_db(empty($dbname)?$this->_config['slave'][$offset]['db']:$dbname,$ _link) 或die( " 資料庫名稱".$this->_config['slave'][$offset]['db']." 不存在。");
 mysql_query("設定名稱utf8" ,$_link);
 return $_link;
 }
 /**
 * 執行資料庫查詢
 * Enter description here ...
 * @param string $sql
*/
 公用函數查詢($sql,$master=true){
 if($master == true || (substr(strtolower($sql),0,6) != 'select') && $master == false){
 $this->_res = mysql_query($ sql ,$this->_master);
 if(!$this->_res){
 $this->_error[] = mysql_error($this->_master);
 }
 $ this->_flag = 'master';
 $this->_link = $this->_master;
 } else {
 $this->_res = mysql_query($sql ,$this->_slave) ;
 if(!$this->_res){
 $this->_error[] = mysql_error($this->_slave);
 }
 $this->_flag = 'slave' ;
 $this->_link = $this->_slave;
 }
 return $this->_res;
 }

 /**
 * 取得單行記錄
 * Enter description here ...
 * @param mixed $rs
*/
 public function get($rs=''){
 if(empty($rs) ){
 $rs = $this->_res;
 }
 return mysql_fetch_row($rs);
 }

 /**
 * 取得多行記錄
 * Enter description here ...
 * @param mixed $rs
 * @param $result_type
*/
 public function fetch($rs = ''){
 if(empty($rs)) {
 $rs = $this->_res;
 }
 return mysql_fetch_array($rs,MYSQL_ASSOC) );
 }

 /**
 * 插入資料
 * Enter description here ...
 * @param unknown_type $sql
/
 * 更新資料
 * Enter description here ...
 * @param unknown_type $sql
*/
 public function add($sql){
 $rs = $this->query($sql);
 if($rs)
 return mysql_insert_id($this->_link);
 return false;
 }

 /**
 * 取得上一語句影響的行數
 * Enter description here ...
*/
 公用函數更新($sql){
 if(empty($sql)) return false;
 $rs = $this->query($sql);
 if($rs)
 return $this ->fetchNum();
 return false;
 }
 /**
 * 析構函數,釋放資料庫連線資源
 * Enter description here ...
*/
 public function fetchNum(){
 return mysql_affected_rows($this->_link);
 }

 /***/* 🎜> public function __destruct(){
 mysql_close($this->_link);
 }
}