Error en sql_a_array

Debido a: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 p.propiedad = db.propiedad and en_internet = 'S' group by b' at line 7

En la consulta 'select b.barrio,b.nombre from datos db, barrios b, propiedades p where p.inmobiliaria = 'CU' and db.campo = 3 and db.valor = b.barrio and b.region= and p.propiedad = db.propiedad and en_internet = 'S' group by b.barrio,b.nombre order by b.nombre'