Try to use views instead of table names, because views have NodeGUID column (and all other columns for pages). So your query will look like:
SELECT ##TOPN##
c.ShowPromoContent,
c.Promo_1,
c.Promo_2,
c.Promo_3,
p.TitleTextLight,
p.TitleTextBold,
p.Description,
p.Image,
p.LinkURL,
p.LinkText
--view name format is Views_(table name)_Joined and you can find it in DB
FROM View_custom_Collections_Detail_Page_Joined c, View_ustom_Promo_Joined p
WHERE ##WHERE##
And use where conditions which were mentioned by Peter.