PHP wpdb::db_connect方法代码示例

 /**
  *	kick()
  *	
  *	Kicks the database to see if the conenction is still alive and if it isn't then tries to reconnect
  *	
  *	@return		true if connection alive (may have been reconnected), false otherwise (dead and couldn't be reconnected)
  *
  */
 public function kick()
 {
     // Initialize result to assume failure
     $result = false;
     // Use ping to check if server is still present - note will not reconnect automatically for MySQL >= 5.0.13
     // and actually we don't want it to as that is bad karma
     if (!mysql_ping($this->_db->dbh)) {
         // Database connection appears to have gone away
         pb_backupbuddy::status(self::STATUS_TYPE_DETAILS, __('Database Server has gone away, attempting to reconnect.', 'it-l10n-backupbuddy'));
         // Close things down cleanly (from a local perspective)
         @mysql_close($this->_db->dbh);
         unset($this->_db->dbh);
         $this->_db->ready = false;
         // And attempt to reconnect
         $this->_db->db_connect();
         // Reconnect failed if we have a null resource or ping fails
         if (NULL == $this->_db->dbh || !mysql_ping($this->_db->dbh)) {
             // Reconnection failed, make sure user knows
             pb_backupbuddy::status(self::STATUS_TYPE_DETAILS, __('Database Server reconnection failed.', 'it-l10n-backupbuddy'));
             // Make sure failure is notified (no need to close things down locally as it's a wrap anyway)
             $result = false;
         } else {
             // Reconnection successful, make sure user knows
             pb_backupbuddy::status(self::STATUS_TYPE_DETAILS, __('Database Server reconnection successful.', 'it-l10n-backupbuddy'));
             $result = true;
         }
     } else {
         // Just to let user know that database is still connected
         pb_backupbuddy::status(self::STATUS_TYPE_DETAILS, __('Database Server connection status verified.', 'it-l10n-backupbuddy'));
         $result = true;
     }
     return $result;
 }

 /**
  * Figure out which db server should handle the query, and connect to it
  *
  * @param string query
  *
  * @return resource MySQL database connection
  */
 public function db_connect($query = '')
 {
     if (empty($query)) {
         return false;
     }
     $this->last_table = $this->table = $this->get_table_from_query($query);
     // Use current table with no callback results
     if (isset($this->ludicrous_tables[$this->table])) {
         $dataset = $this->ludicrous_tables[$this->table];
         $this->callback_result = null;
         // Run callbacks and either extract or update dataset
     } else {
         // Run callbacks and get result
         $this->callback_result = $this->run_callbacks('dataset', $query);
         // Set if not null
         if (!is_null($this->callback_result)) {
             if (is_array($this->callback_result)) {
                 extract($this->callback_result, EXTR_OVERWRITE);
             } else {
                 $dataset = $this->callback_result;
             }
         }
     }
     if (!isset($dataset)) {
         $dataset = 'global';
     }
     if (empty($dataset)) {
         return $this->bail("Unable to determine which dataset to query. ({$this->table})");
     } else {
         $this->dataset = $dataset;
     }
     $this->run_callbacks('dataset_found', $dataset);
     if (empty($this->ludicrous_servers)) {
         if ($this->dbh_type_check($this->dbh)) {
             return $this->dbh;
         }
         if (!defined('DB_HOST') || !defined('DB_USER') || !defined('DB_PASSWORD') || !defined('DB_NAME')) {
             return $this->bail('We were unable to query because there was no database defined.');
         }
         // Fallback to wpdb db_connect method.
         $this->dbuser = DB_USER;
         $this->dbpassword = DB_PASSWORD;
         $this->dbname = DB_NAME;
         $this->dbhost = DB_HOST;
         parent::db_connect();
         return $this->dbh;
     }
     // Determine whether the query must be sent to the master (a writable server)
     if (!empty($use_master) || $this->srtm === true || isset($this->srtm[$this->table])) {
         $use_master = true;
     } elseif ($is_write = $this->is_write_query($query)) {
         $use_master = true;
         if (is_array($this->srtm)) {
             $this->srtm[$this->table] = true;
         }
         // Detect queries that have a join in the srtm array.
     } elseif (!isset($use_master) && is_array($this->srtm) && !empty($this->srtm)) {
         $use_master = false;
         $query_match = substr($query, 0, 1000);
         foreach ($this->srtm as $key => $value) {
             if (false !== stripos($query_match, $key)) {
                 $use_master = true;
                 break;
             }
         }
     } else {
         $use_master = false;
     }
     if (!empty($use_master)) {
         $this->dbhname = $dbhname = $dataset . '__w';
         $operation = 'write';
     } else {
         $this->dbhname = $dbhname = $dataset . '__r';
         $operation = 'read';
     }
     // Try to reuse an existing connection
     while (isset($this->dbhs[$dbhname]) && $this->dbh_type_check($this->dbhs[$dbhname])) {
         // Find the connection for incrementing counters
         foreach (array_keys($this->db_connections) as $i) {
             if ($this->db_connections[$i]['dbhname'] == $dbhname) {
                 $conn =& $this->db_connections[$i];
             }
         }
         if (isset($server['name'])) {
             $name = $server['name'];
             // A callback has specified a database name so it's possible the
             // existing connection selected a different one.
             if ($name != $this->used_servers[$dbhname]['name']) {
                 if (!$this->select($name, $this->dbhs[$dbhname])) {
                     // this can happen when the user varies and lacks permission on the $name database
                     if (isset($conn['disconnect (select failed)'])) {
                         ++$conn['disconnect (select failed)'];
                     } else {
//.........这里部分代码省略.........

 private function restoreWpdbConnection()
 {
     if (!class_exists('wpdb')) {
         return;
     }
     /** @var \wpdb $wpdb */
     global $wpdb;
     if (empty($wpdb)) {
         $wpdb = new \wpdb(DB_USER, DB_PASSWORD, DB_NAME, DB_HOST);
     } else {
         $wpdb->db_connect();
         $wpdb->check_connection();
     }
     /**
      * To avoid `mysqli_free_result` errors during the `wpdb::flush()` method set the result to `null`.
      * See `wp-db.php` file line 1425.
      */
     $reflection = new \ReflectionClass($wpdb);
     $resultProperty = $reflection->getProperty('result');
     $resultProperty->setAccessible(true);
     $resultProperty->setValue($wpdb, null);
     $resultProperty->setAccessible(false);
 }