Špatný dotaz: Unknown column 'na' in 'where clause'
SELECT id,nazev,poradi,text,zkracene,url,id_kategorie,kod,datum,datum_zobrazovat FROM prispevek WHERE zobrazovat="A" AND (id_kategorie in(na-nasi-skole-se-stale-neco-deje-prijdte-se-presvedcit-na-vystavu-vzdelani-a-remeslo-nebo-na-dny-otevrenych-dveri) or exists(select * from prispevek_kategorie pk where pk.id_prispevek = prispevek.id and pk.id_kategorie in (na-nasi-skole-se-stale-neco-deje-prijdte-se-presvedcit-na-vystavu-vzdelani-a-remeslo-nebo-na-dny-otevrenych-dveri))) order by datum DESC ,id DESC