php PDOÅжÏÁ¬½ÓÊÇ·ñ¿ÉÓõÄʵÏÖ·½·¨

mysql_ping() ¼i²eµ½þÎñÆ÷µÄÁ¬½ÓÊÇñÕý³£¡£Èç¹uµ½þÎñÆ÷µÄÁ¬½Ó¿ÉÓã¬Ôoµ»Øtrue£¬ñÔoµ»Øfalse¡£

µ«PDO²»Ö§³Ö**mysql_ping()**½¨£¬Òo´ËÐeÒª×Ô¼º±aд´uÂeÄ£Äamysql_ping()½¨£¬¼i²eÁ¬½ÓÊÇ*ñ¿ÉÓá£

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    <?php
    /**
     * ¼i²eÁ¬½ÓÊÇ*ñ¿ÉÓÃ
     * @param Link $dbconn Êý¾Ý¿aÁ¬½Ó
     * @return Boolean
     */
    function pdo_ping($dbconn){
      try{
        $dbconn->getAttribute(PDO::ATTR_SERVER_INFO);
      } catch (PDOException $e) {
        if(strpos($e->getMessage(), 'MySQL server has gone away')!==false){
          return false;
        }
      }
      return true;
    }
    ?>

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1¡¢´´½¨²aÊÔÊý¾Ý±i

    CREATE TABLE `user` (
     `id` int(11) unsigned NOT NULL AUTO_INCREMENT,
     `name` varchar(20) NOT NULL,
     PRIMARY KEY (`id`)
    ) ENGINE=InnoDB DEFAULT CHARSET=utf8;

2¡¢²aÈe²aÊÔÊý¾Ý

    insert into user(name) values('fdipzone'),('xfdipzone'),('terry');

    mysql> select * from user;
    +----+-----------+
    | id | name   |
    +----+-----------+
    | 1 | fdipzone |
    | 2 | xfdipzone |
    | 3 | terry   |
    +----+-----------+

3¡¢ÑÝʾÎļþ

db.php

    <?php
    // Êý¾Ý¿a²Ù×÷Àa
    class DB{

      // ±£´aeÊý¾Ý¿aÁ¬½Ó
      private static $_instance = null;

      // Á¬½ÓÊý¾Ý¿a
      public static function get_conn($config){
        if(isset(self::$_instance) && !empty(self::$_instance)){
          return self::$_instance;
        }

        $dbhost = $config['host'];
        $dbname = $config['dbname'];
        $dbuser = $config['user'];
        $dbpasswd = $config['password'];
        $pconnect = $config['pconnect'];
        $charset = $config['charset'];

        $dsn = "mysql:host=$dbhost;dbname=$dbname;";
        try {
          $h_param = array(
              PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION,
          );
          if ($charset != '') {
            $h_param[PDO::MYSQL_ATTR_INIT_COMMAND] = 'SET NAMES ' . $charset; //ÔOÖÃĬÕJ¾Ž´a
          }
          if ($pconnect) {
            $h_param[PDO::ATTR_PERSISTENT] = true;
          }
          $conn = new PDO($dsn, $dbuser, $dbpasswd, $h_param);

        } catch (PDOException $e) {
          throw new ErrorException('Unable to connect to db server. Error:' . $e->getMessage(), 31);
        }

        self::$_instance = $conn;
        return $conn;
      }

      // Ö´Ðвeѯ
      public static function query($dbconn, $sqlstr, $condparam){
        $sth = $dbconn->prepare($sqlstr);
        try{
          $sth->execute($condparam);
        } catch (PDOException $e) {
          echo $e->getMessage().PHP_EOL;
        }
        $result = $sth->fetchAll(PDO::FETCH_ASSOC);
        return $result;
      }

      // ÖØÖÃÁ¬½Ó
      public static function reset_connect(){
        self::$_instance = null;
      }

    }
    ?>

test.php

    <?php
    require 'db.php';

    // Êý¾Ý¿aÉe¶¨
    $config = array(
      'host' => 'localhost',
      'dbname' => 'user',
      'user' => 'root',
      'password' => '',
      'pconnect' => 0,
      'charset' => ''
    );

    // Ñ­»*Ö´ÐÐ
    while(true){

      // ´´½¨Êý¾ÝÁ¬½Ó
      $dbconn = DB::get_conn($config);

      // ÅжÏÁ¬½ÓÊÇ*ñÓÐЧ
      $status = pdo_ping($dbconn);

      if($status){
        echo 'connect ok'.PHP_EOL;
      }else{
        echo 'connect failure'.PHP_EOL;

        // ÖØÖÃÁ¬½Ó
        DB::reset_connect();
        $dbconn = DB::get_conn($config);
      }

      // Ö´Ðвeѯ
      $sqlstr = 'select * from user where id=?';
      $condparam = array(mt_rand(1,3));
      $data = DB::query($dbconn, $sqlstr, $condparam);
      print_r($data);

      // ÑÓʱ10Ãe
      echo 'sleep 10'.PHP_EOL.PHP_EOL;
      sleep(10);

    }

    /**
     * ¼i²eÁ¬½ÓÊÇ*ñ¿ÉÓÃ
     * @param Link $dbconn Êý¾Ý¿aÁ¬½Ó
     * @return Boolean
     */
    function pdo_ping($dbconn){
      try{
        $dbconn->getAttribute(PDO::ATTR_SERVER_INFO);
      } catch (PDOException $e) {
        if(strpos($e->getMessage(), 'MySQL server has gone away')!==false){
          return false;
        }
      }
      return true;
    }
    ?>

4¡¢Ö´ÐÐ

ÔÚphp cliģʽÏÂÖ´ÐÐtest.php£¬È»ºoÂiÉÏÖ´ÐÐmysql.server stop Óe mysql.server start Ä£ÄaÉÁ¶Ï

    mysql.server stop
    Shutting down MySQL
    .... SUCCESS! 
    mysql.server start
    Starting MySQL
     SUCCESS! 

Ö´ÐÐÊa³o£º

    connect ok
    Array
    (
      [0] => Array
        (
          [id] => 2
          [name] => xfdipzone
        )

    )
    sleep 10

    connect failure
    Array
    (
      [0] => Array
        (
          [id] => 3
          [name] => terry
        )

    )
    sleep 10

    connect ok
    Array
    (
      [0] => Array
        (
          [id] => 3
          [name] => terry
        )

    )
    sleep 10

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