lib/dml/pgsql_native_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  * Native postgresql 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 require_once(__DIR__.'/moodle_recordset.php');
  28
  29 /**
  30  * pgsql specific moodle recordset class
  31  *
  32  * @package    core_dml
  33  * @copyright  2008 Petr Skoda (http://skodak.org)
  34  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  35  */
  36 class pgsql_native_moodle_recordset extends moodle_recordset {
  37
  38     protected $result;
  39     /** @var current row as array.*/
  40     protected $current;
  41     protected $bytea_oid;
  42     protected $blobs = array();
  43
  44     public function __construct($result, $bytea_oid) {
  45         $this->result    = $result;
  46         $this->bytea_oid = $bytea_oid;
  47
  48         // find out if there are any blobs
  49         $numrows = pg_num_fields($result);
  50         for($i=0; $i<$numrows; $i++) {
  51             $type_oid = pg_field_type_oid($result, $i);
  52             if ($type_oid == $this->bytea_oid) {
  53                 $this->blobs[] = pg_field_name($result, $i);
  54             }
  55         }
  56
  57         $this->current = $this->fetch_next();
  58     }
  59
  60     public function __destruct() {
  61         $this->close();
  62     }
  63
  64     private function fetch_next() {
  65         if (!$this->result) {
  66             return false;
  67         }
  68         if (!$row = pg_fetch_assoc($this->result)) {
  69             pg_free_result($this->result);
  70             $this->result = null;
  71             return false;
  72         }
  73
  74         if ($this->blobs) {
  75             foreach ($this->blobs as $blob) {
  76                 $row[$blob] = $row[$blob] !== null ? pg_unescape_bytea($row[$blob]) : null;
  77             }
  78         }
  79
  80         return $row;
  81     }
  82
  83     public function current() {
  84         return (object)$this->current;
  85     }
  86
  87     public function key() {
  88         // return first column value as key
  89         if (!$this->current) {
  90             return false;
  91         }
  92         $key = reset($this->current);
  93         return $key;
  94     }
  95
  96     public function next() {
  97         $this->current = $this->fetch_next();
  98     }
  99
 100     public function valid() {
 101         return !empty($this->current);
 102     }
 103
 104     public function close() {
 105         if ($this->result) {
 106             pg_free_result($this->result);
 107             $this->result  = null;
 108         }
 109         $this->current = null;
 110         $this->blobs   = null;
 111     }
 112 }