[ContraVeneno]

prueba con

Código SQL [-]
select 
a.id_cliente,   
a.id_deudor,                               
a.nombre,
b.id_deudor,
b.fecha_gestion,
b.observaciones                                 
from deduroes a 
left outer join a.id_deudor=b.id_deudor
where a.id_cliente=1 and b.fecha_gestion between '01/01/2007' and '01/01/2007'

left outer