$db->query("INSERT INTO `{$DT_PRE}table` (`xxx`) VALUES ('yyy')");

$db->query("UPDATE `{$DT_PRE}table` SET `xxx`='yyy' WHERE `zzz`=1");

$db->query("DELETE FROM `{$DT_PRE}table` WHERE `zzz`=1");

$A = array();
$result = $db->query("SELECT * FROM `{$DT_PRE}table` WHERE `xxx`='yyy' ORDER BY `zzz` DESC LIMIT 0,10");
while($r = $db->fetch_array($result)) {
  $A[] = $r;
}
print_r($A);

$A = $db->get_one("SELECT * FROM `{$DT_PRE}table` WHERE `xxx`='yyy'");
print_r($A);

$A = $db->get_one("SELECT COUNT(*) AS num FROM `{$DT_PRE}table` WHERE `xxx`='yyy'");
echo $A['num'];