Expression #1 of ORDER BY clause is not in SELECT list, references column 'zimmerimor_new1.SitesPages.PagesOrder' which is not in SELECT list; this is incompatible with DISTINCT
SELECT DISTINCT SitesPages.MainPageID, Pages.PageID FROM SitesPages LEFT JOIN MainPages USING(MainPageID) LEFT JOIN Pages USING(MainPageID) WHERE siteID = 144 AND LangID = 1 ORDER BY SitesPages.PagesOrder LIMIT 0,1