lib/dml/moodle_recordset.php

   1 <?php
   2 // This file is part of Moodle - http://moodle.org/
   3 //
   4 // Moodle is free software: you can redistribute it and/or modify
   5 // it under the terms of the GNU General Public License as published by
   6 // the Free Software Foundation, either version 3 of the License, or
   7 // (at your option) any later version.
   8 //
   9 // Moodle is distributed in the hope that it will be useful,
  10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 // GNU General Public License for more details.
  13 //
  14 // You should have received a copy of the GNU General Public License
  15 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
  16
  17 /**
  18  * Abstract recordset.
  19  *
  20  * @package    core_dml
  21  * @copyright  2008 Petr Skoda (http://skodak.org)
  22  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  23  */
  24
  25 defined('MOODLE_INTERNAL') || die();
  26
  27 /**
  28  * Abstract class for resultsets returned from database functions.
  29  * This is a simple Iterator with needed recorset closing support.
  30  *
  31  * The difference from old recorset is that the records are returned
  32  * as objects, not arrays. You should use "foreach ($recordset as $record) {}"
  33  * followed by "$recordset->close()".
  34  *
  35  * Do not forget to close all recordsets when they are not needed anymore!
  36  */
  37 abstract class moodle_recordset implements Iterator {
  38
  39     /**
  40      * Returns current record - fields as object properties, lowercase
  41      * @return object
  42      */
  43     //public abstract function current();
  44
  45     /**
  46      * Returns the key of current row
  47      * @return int current row
  48      */
  49     //public abstract function key();
  50
  51     /**
  52      * Moves forward to next row
  53      * @return void
  54      */
  55     //public abstract function next();
  56
  57     /**
  58      * Rewinds are not supported!
  59      * @return void
  60      */
  61     public function rewind(): void {
  62         // no seeking, sorry - let's ignore it ;-)
  63         return;
  64     }
  65
  66     /**
  67      * Did we reach the end?
  68      * @return boolean
  69      */
  70     //public abstract function valid();
  71
  72     /**
  73      * Free resources and connections, recordset can not be used anymore.
  74      * @return void
  75      */
  76     abstract public function close();
  77 }