No se pudo ejecutar la consulta

SELECT id,name,title,preparacion,ingredientes,rating,votes,sumofvotes,time FROM wsnlinks_receta WHERE catid =  AND folderid = 0

Error MySQL: : You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'AND folderid = 0' at line 1

Este Script no puede continuar.