update training set class = 0;

delete train1 from training train1, training train2
where
    train1.id > train2.id and
    train1.message = train2.message;

update training
    set class = 1
where
    (message like '%.com %' or
    message like '%.net %' or
    message like '%.de %') and
    message not like '%your-domain.de %' and
    message not like '%your-other-domain.com%' and
    message not like '%youtube.com%' and
    message not like '%facebook.com%' and
    class = 0;