15     protected $db;  variable in helper_plugin_questionnaire
24         if ($this->db === null) {
26                 $this->db = new SQLiteDB('questionnaire', DOKU_PLUGIN . 'questionnaire/db/');
27                 $this->db->getPdo()->exec('PRAGMA foreign_keys = ON');
35         return $this->db;
46         $db = $this->getDB();
47         if (!$db) return null;
50         return $db->queryRecord($sql, $page);
62         $db = $this->getDB();
72         $db->saveRecord('questionnaires', $record);
84         $db = $this->getDB();
86         $record = $db->queryRecord('SELECT * FROM questionnaires WHERE page = ?', $page);
91         $db->saveRecord('questionnaires', $record);
103         $db = $this->getDB();
104         if (!$db) return false;
107         return $db->queryValue($sql, $page, $user) > 0;
118         $db = $this->getDB();
119         if (!$db) return 0;
122         return (int)$db->queryValue($sql, $page);
146         $db = $this->getDB();
147         if (!$db) return [];
150         return array_column($db->queryAll($sql, $page), 'question');