php下mysqldb读写分离操作类

/**
* php MysqlDB 读写分离类
* -----------------------------------------------------
* $Author: Bevin Chen $
* $Email: bevin#chenapp.com $
* $Date: 2009-10-10 $
* -----------------------------------------------------
*/

class mysqldb {
var $querynum = 0;
var $linkr,$linkw,$charset,$pconnect,$dbconfig;

function __constructor($dbarray) {
   $this->mysqldb($dbarray);
}

function mysqldb($dbarray,$dbcharset='utf8',$pcontent=0) {
   if(!is_array($dbarray[0])) {
    echo "数据库参数错误";
    return false;
   }
   $this->charset = $dbcharset;
   $this->pconnect = $pconnect;
   $this->dbconfig['master'] = $dbarray[0];
   $dbServerNum = count($dbarray);
   if($dbServerNum > 1) {
    /*
    * 当x=1 时，$dbarray[0]不作slave
    * 当x=0 时，$dbarray[0]作slave
    */
    $x = 1;
    $rand = rand($x,$dbServerNum-1);
    $this->dbconfig['slave'] = $dbarray[$rand];
   } else {
    $this->dbconfig['slave'] = false;
   }
}

function connect($dbhost,$dbuser,$dbpw,$dbname) {
   if($this->pconnect) {
    $link = @mysql_pconnect($dbhost, $dbuser, $dbpw);
   } else {
    $link = @mysql_connect($dbhost, $dbuser, $dbpw, 1);
   }
   if($link) {
    if($this->version($link) > '4.1') {
     if($this->charset) {
      @mysql_query("SET character_set_connection=".$this->charset.", character_set_results=".$this->charset.", character_set_client=binary", $link);
     }

     if($this->version($link) > '5.0.1') {
      @mysql_query("SET sql_mode=''", $link);
     }
    }

    if($dbname) {
     @mysql_select_db($dbname, $link);
    }
    //print_r($link);
    return $link;
   } else {
    return false;
   }
}

function connectM() {
   if(!$this->linkw = $this->connect($this->dbconfig['master'][0],$this->dbconfig['master'][1],$this->dbconfig['master'][2],$this->dbconfig['master'][3])) {
    exit("主数据库连接失败！");
   }
   //echo "<br>##connectM!.<br>";
}

function connectS() {
   if($this->dbconfig['slave']) {
    if(!$this->linkr = $this->connect($this->dbconfig['slave'][0],$this->dbconfig['slave'][1],$this->dbconfig['slave'][2],$this->dbconfig['slave'][3])) {
     $this->dbconfig['slave'] = false;
     $this->connectS();
    }
    //echo "<br>##connectS!.<br>";
   } else {
    if(!$this->linkw) {
     $this->connectM();
    }
    $this->linkr = $this->linkw;
   }
}

// db read
function query($sql, $type = '') {
   if(!$this->linkr) {
    $this->connectS();
   }
   $func = $type == 'UNBUFFERED' && @function_exists('mysql_unbuffered_query') ?
    'mysql_unbuffered_query' : 'mysql_query';
   $query = $func($sql, $this->linkr);

   $this->querynum++;
   return $query;
}

function fetch_array($query, $result_type = MYSQL_ASSOC) {
   return @mysql_fetch_array($query, $result_type);
}

function fetch_row($query) {
   $query = mysql_fetch_row($query);
   return $query;
}

function fetch_One($sql) {
   $query = $this->query($sql);
   return $this->fetch_row($query);
}

/* 获取分页方法 */
function fetch_page($sql, $pagenum) {
   $page = intval($_GET['page']);

   $query = $this->query($sql);
   $countnum = $this->num_rows($query);
   $countpage = ceil($countnum/$pagenum);

   if($page<1) { $page=1; }
   if($page>$countpage) { $page=$countpage; }
  
   $limitstart = ($page-1)*$pagenum;
  
   /* 获取数据结果集 */
   for($i=0; $i<($limitstart+$pagenum); $i++) {
    if($i>=$countnum) { break; }
    if($i>=$limitstart) {
     $result[] = $this->fetch_array($query);
    } else {
     $this->fetch_array($query);
    }
   }

   /* 生成url */
   $url = $_SERVER['QUERY_STRING'];
   $url = preg_replace("/&?page=[0-9]+/i","",$url);

   $array['countnum'] = $countnum;
   $array['countpage'] = $countpage;
   $array['result'] = $result;
   $array['page'] = $page;
   if($page>1) {
    $array['preurl'] = "?".$url."&page=".($page-1);
    $array['prepage'] = $page-1;
   } else {
    $array['preurl'] = "?".$url."&page=1";
    $array['prepage'] = 1;
   }
   if($page<$countpage) {
    $array['nexturl'] = "?".$url."&page=".($page+1);
    $array['nextpage'] = $page+1;
   } else {
    $array['nexturl'] = "?".$url."&page=".$countpage;
    $array['nextpage'] = $countpage;
   }
   $array['firsturl'] = "?".$url."&page=1";
   $array['firstpage'] = 1;
   $array['lasturl'] = "?".$url."&page=".$countpage;
   $array['lastpage'] = $countpage;
   $array['nopage'] = "?".$url."&page=";
  
   return $array;
}

// db write
function queryw($sql, $type = '') {
   if(!$this->linkw) {
    $this->connectM();
   }
   $func = $type == 'UNBUFFERED' && @function_exists('mysql_unbuffered_query') ?
    'mysql_unbuffered_query' : 'mysql_query';
   $query = $func($sql, $this->linkw);

   $this->querynum++;
   return $query;
}

function update($table,$where,$array) {
   $whereset = $set = $dot = '';
   foreach($array as $key=>$value) {
    $set .= $dot." `$key`='$value'";
    $dot = ',';
   }
   $whereset = $dot = '';
   foreach($where as $k=>$v) {
    $whereset .= $dot." `$k`='$v'";
    $dot = ' and ';
   }

   $sql = "update $table set $set where $whereset";
   return $this->queryw($sql);
}

function insert($table,$array) {
   $col = $v = $dot = '';
   foreach($array as $key=>$value) {
    $v .= $dot."'$value'";
    $col .= $dot."`$key`";
    $dot = ',';
   }
   $sql = "insert into $table ($col) values ($v)";
   if($this->queryw($sql)) {
    return $this->insert_id();
   } else {
    return false;
   }
}

function insert_id() {
   return ($id = mysql_insert_id($this->linkw)) >= 0 ? $id : $this->result($this->queryw("SELECT last_insert_id()"), 0);
}

// db other
function affected_rows($link) {
   return mysql_affected_rows($link);
}

function error($link) {
   return (($link) ? mysql_error($link) : mysql_error());
}

function errno($link) {
   return intval(($link) ? mysql_errno($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 fetch_fields($query) {
   return mysql_fetch_field($query);
}

function version($link) {
   return mysql_get_server_info($link);
}

function close($link) {
   return mysql_close($link);
}
}

/* 测试例子 //
* $dbarray[] = array('localhost','bevin','password','test');
* $dbarray[] = array('chenapp.com','root','password','test');
* $dbarray[] = array('192.168.1.77','cxh','password','test');
* $newdb = new mysqldb($dbarray,'utf8');
* $array = array('name' => date("Y-m-d H:i:s"));
* $id = $newdb->insert("test",$array);
* $result = $newdb->fetch_page("select * from test order by id desc",'10');
* print_r($result);
* $id = $newdb->insert("test",$array);
* echo $id;
*/