SQL hiba!

kiemelt

(select * from olt__szallas where cat= and node_cityname='' and kiem=1) union (select * from olt__szallas where cat= and node_cityname='' and kiem=0)

You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'and node_cityname='' and kiem=1) union (select * from olt__szallas where cat...' at line 1