php pdo中的AND - OR操作符


AND - OR operators in php pdo

php中是否有OR操作符?

我写了这段代码,但不工作,因为我使用了OR操作符:

$trebanam = 'seme';
$trebanam1 = 'sadnice';

    # basic pdo connection (with added option for error handling)
if(!empty($_SERVER['HTTP_X_REQUESTED_WITH']) && strtolower($_SERVER['HTTP_X_REQUESTED_WITH']) == 'xmlhttprequest') { 
     $statement=$db->prepare("SELECT id,vrsta,artikl,bruto_kol FROM zalihe WHERE user_id=:user_id AND vrsta=:trebanam OR vrsta=:trebanam1");
$statement->execute(array(':user_id' => $user_id, ':trebanam'=>$trebanam, ':trebanam'=>$trebanam1));
$results=$statement->fetchAll(PDO::FETCH_ASSOC);
$json=json_encode($results);
echo $json;
     }
    else { 
echo 'GRESKA 404';
    }
    ?>

所以这里我需要得到vrsta = seme或vrsta = sadnice的数据…我怎么能做到呢?有可能像我那样做吗?

OR条件需要适当的括号

WHERE user_id=:user_id AND ( vrsta=:trebanam OR vrsta=:trebanam1 )