gistfile1.txt

get empty winners id's:

SELECT DISTINCT w.winner_id FROM winners w join winner_metas m on w.winner_id=m.winner_id
WHERE (m.meta_name='lastName' AND m.meta_data='') OR (m.meta_name='firstName' AND m.meta_data='') OR (m.meta_name='twitterUserName' AND m.meta_data='')
ORDER BY w.winner_id DESC;

get distinct surnames or twitter users:

SELECT m.meta_data, w.winner_id FROM winners w join winner_metas m on w.winner_id=m.winner_id
WHERE m.meta_name='twitterUserName' OR m.meta_name='lastName'
GROUP BY m.meta_data
ORDER BY m.meta_data ASC;