MYSQL实现主从insert和query分开操作

dbConfig = $dbConfig;            $this->multi_server = empty ( $this->dbConfig['slave'] ) ? false : true;   }   /**    * 连接数据库方法    * @param type $dbConfig     */   public function connect ($db) {      $this->dbCurrent = $db;      $linkfunction = ( TRUE == $db['persistent'] ) ? 'mysql_pconnect' : 'mysql_connect';      $this->conn = $linkfunction ( $db ['host'], $db ['username'], $db ['password']);      if (! $this->conn) {            return false;      }      $re = mysql_select_db($db['dbname'], $this->conn);      if(!$re) {         return false;      }      mysql_query ( "SET NAMES '" . $db ['charset'] . "'", $this->conn );               }      /**    * 初始化数据库连接    * @param type $master     */   public function initConnect ($master = true) {      if ($master || !$this->multi_server) {            if($this->m_link_id){                  $this->conn = $this->m_link_id;                  $this->ping($master);            } else {                  $this->connect ( $this->dbConfig ['master'] );                  $this->m_link_id = $this->conn;            }      } else {            if($this->s_link_id){                  $this->conn = $this->s_link_id;                  $this->ping($master);            } else {                  $rand = rand(0, count($this->dbConfig ['slave']) - 1);                  $this->connect ( $this->dbConfig ['slave'][$rand] );                  $this->s_link_id = $this->conn;            }      }    }    /**    * 按SQL语句获取记录结果，返回数组    *    * @param sql  执行的SQL语句    */   public function getArray($sql)   {      if( ! $result = $this->query($sql) )return FALSE;      if( ! mysql_num_rows($result) ) return FALSE;      $rows = array();      while($rows[] = mysql_fetch_array($result,MYSQL_ASSOC)){}      mysql_free_result($result);      array_pop($rows);      return $rows;   }   /**    * 返回当前插入记录的主键ID    */   public function newinsertid()   {      return mysql_insert_id($this->conn);   }   /**    * 格式化带limit的SQL语句    */   public function setlimit($sql, $limit)   {      return $sql. " LIMIT {$limit}";   }   /**    * 执行一个SQL语句    *    * @param sql 需要执行的SQL语句    */   public function exec($sql)   {      $this->arrSql[] = $sql;        $this->initConnect ( true );            return mysql_query($sql, $this->conn);   }    /**     * 执行一个SQL语句，主要用于查询     * @param type $sql     * @param type $master default:false 为true:强制读主库；为false：在有从库的的情况下优先读从库，否则读主库     */    public function query ($sql, $master = false) {        $this->arrSql[] = $sql;        $this->initConnect ( $master );        return mysql_query($sql, $this->conn);    }   /**    * 返回影响行数    */   public function affected_rows()   {      return mysql_affected_rows($this->conn);   }   /**    * 获取数据表结构    *    * @param tbl_name  表名称    */   public function getTable($tbl_name)   {      return $this->getArray("DESCRIBE {$tbl_name}");   }       //防止mysql gone away    public function ping($master) {       if(!@mysql_ping($this->conn)){         @mysql_close($this->conn); //注意：一定要先执行数据库关闭，这是关键         if($master || !$this->multi_server) {            unset($this->m_link_id);         } else {            unset($this->s_link_id);         }         $this->initConnect($master);      }    }       /**    * 对特殊字符进行过滤    *    * @param value  值    */   public function __val_escape($value) {      if(is_null($value))return 'NULL';      if(is_bool($value))return $value ? 1 : 0;      if(is_int($value))return (int)$value;      if(is_float($value))return (float)$value;      if(@get_magic_quotes_gpc())$value = stripslashes($value);        $this->conn || $this->initConnect();      return '\''.mysql_real_escape_string($value, $this->conn).'\'';   }   public function escape($value) {      if(is_null($value))return 'NULL';      if(is_bool($value))return $value ? 1 : 0;      if(is_int($value))return (int)$value;      if(is_float($value))return (float)$value;      if(@get_magic_quotes_gpc())$value = stripslashes($value);        $this->conn || $this->initConnect();      return mysql_real_escape_string($value, $this->conn);   }      /**    * 析构函数    */   public function __destruct()   {        if( TRUE != @$this->dbCurrent['persistent'] )@mysql_close($this->conn);   }}

重点在 initConnect($master)方法里，这里决定加载的配置文件中是连接到主库还是从库