prova con questa query, visto che il numero di campi è lo stesso (spero non ci siano errori):
Codice PHP:
SELECT events.ide AS id, events.tite AS title, events.imge AS img, events.datae AS data, events.slide AS slide, 'event' AS type
FROM events WHERE slide='s'
UNION SELECT news.idn AS id, news.titn AS title, news.imgn AS img, news.datan AS data,
news.slide AS slide, 'news' AS type
FROM news WHERE slide='s'
ORDER BY data