剖析thinkphp下數據庫讀寫分離代碼

??/** ?????*?SQL查詢 ?????*?@access?public ?????*?@param?string?$sql??SQL ?????*?@param?mixed?$parse??是否需要解析SQL?? ?????*?@return?mixed ?????*/ ????public?function?query($sql,$parse=false)?{ ????????if(!is_bool($parse)?&&?!is_array($parse))?{ ????????????$parse?=?func_get_args(); ????????????array_shift($parse); ????????} ????????$sql??=???$this->parseSql($sql,$parse); ????????return?$this->db->query($sql); ????}

??/** ?????*?執行查詢?返回數據集 ?????*?@access?public ?????*?@param?string?$str??sql指令 ?????*?@return?mixed ?????*/ ????public?function?query($str)?{ ????????if(0===stripos($str,?'call')){?//?存儲過程查詢支持 ????????????$this->close(); ????????????$this->connected????=???false; ????????} ????????$this->initConnect(false); ????????if?(?!$this->_linkID?)?return?false; ????????$this->queryStr?=?$str; ????????//釋放前次的查詢結果 ????????if?(?$this->queryID?)?{????$this->free();????} ????????N('db_query',1); ????????//?記錄開始執行時間 ????????G('queryStartTime'); ????????$this->queryID?=?mysql_query($str,?$this->_linkID); ????????$this->debug(); ????????if?(?false?===?$this->queryID?)?{ ????????????$this->error(); ????????????return?false; ????????}?else?{ ????????????$this->numRows?=?mysql_num_rows($this->queryID); ????????????return?$this->getAll(); ????????} ????}

??/** ?????*?初始化數據庫連接 ?????*?@access?protected ?????*?@param?boolean?$master?主服務器 ?????*?@return?void ?????*/ ????protected?function?initConnect($master=true)?{ ????????if(1?==?C('DB_DEPLOY_TYPE')) ????????????//?采用分布式數據庫 ????????????$this->_linkID?=?$this->multiConnect($master); ????????else ????????????//?默認單數據庫 ????????????if?(?!$this->connected?)?$this->_linkID?=?$this->connect(); ????} ????/** ?????*?連接分布式服務器 ?????*?@access?protected ?????*?@param?boolean?$master?主服務器 ?????*?@return?void ?????*/ ????protected?function?multiConnect($master=false)?{ ????????foreach?($this->config?as?$key=>$val){ ????????????$_config[$key]??????=???explode(',',$val); ????????}???????? ????????//?數據庫讀寫是否分離 ????????if(C('DB_RW_SEPARATE')){ ????????????//?主從式采用讀寫分離 ????????????if($master) ????????????????//?主服務器寫入 ????????????????$r??=???floor(mt_rand(0,C('DB_MASTER_NUM')-1)); ????????????else{ ????????????????if(is_numeric(C('DB_SLAVE_NO')))?{//?指定服務器讀 ????????????????????$r?=?C('DB_SLAVE_NO'); ????????????????}else{ ????????????????????//?讀操作連接從服務器 ????????????????????$r?=?floor(mt_rand(C('DB_MASTER_NUM'),count($_config['hostname'])-1));???//?每次隨機連接的數據庫 ????????????????} ????????????} ????????}else{ ????????????//?讀寫操作不區分服務器 ????????????$r?=?floor(mt_rand(0,count($_config['hostname'])-1));???//?每次隨機連接的數據庫 ????????} ????????$db_config?=?array( ????????????'username'??=>??isset($_config['username'][$r])?$_config['username'][$r]:$_config['username'][0], ????????????'password'??=>??isset($_config['password'][$r])?$_config['password'][$r]:$_config['password'][0], ????????????'hostname'??=>??isset($_config['hostname'][$r])?$_config['hostname'][$r]:$_config['hostname'][0], ????????????'hostport'??=>??isset($_config['hostport'][$r])?$_config['hostport'][$r]:$_config['hostport'][0], ????????????'database'??=>??isset($_config['database'][$r])?$_config['database'][$r]:$_config['database'][0], ????????????'dsn'???????=>??isset($_config['dsn'][$r])?$_config['dsn'][$r]:$_config['dsn'][0], ????????????'params'????=>??isset($_config['params'][$r])?$_config['params'][$r]:$_config['params'][0], ????????????'charset'???=>??isset($_config['charset'][$r])?$_config['charset'][$r]:$_config['charset'][0],???????????? ????????); ????????return?$this->connect($db_config,$r); ????}