14     private $db = null;  variable in helper_plugin_issuelinks_db
26         $db = $this->getDB();
27         if (!$db) {
31         $db->query($sql, [$key, $value]);
44         if (null === $this->db) {
65             $this->db = $sqlite;
67         return $this->db;
77         $db = $this->getDB();
78         if (!$db) return;
80         $db->query('DELETE FROM issues');
81         $db->query('DELETE FROM issue_issues');
82         $db->query('DELETE FROM pagerev_issues');
83         $db->query('VACUUM');
95         $db = $this->getDB();
96         if (!$db) {
100         $res = $db->query($sql, [$key]);
101         $value = $db->res2single($res);
102         $db->res_close($res);
134         $db = $this->getDB();
135         if (!$db) {
144         $ok = $db->query($sql, $vals);
187         $db = $this->getDB();
188         if (!$db) {
192         $res = $db->query($sql, $conditional);
193         $result = $db->res2arr($res);
194         $db->res_close($res);
221         $db = $this->getDB();
222         if (!$db) {
230         $db->query($sql, $vals);