SQL MAX in WHERE

Question

select contract.id, invoice.period_to 
from public.invoice 
right join public.contract on invoice.contract_id = contract.id 
where (MAX(invoice.period_to) <= '2017-10-01' OR invoice.id IS NULL) 
     ^^^^^^^^^^^^^^^^^^^^^ - I need help here 
AND contract.close_type IS NULL 
    AND contract.payment_type != 'TRIAL' 
    group by contract.id; 

Ich weiß, ich MAX unter Verwendung kippe WHERE so im versuchen, so etwas wie

where (invoice.period_to IN(SELECT MAX(invoice.period_to) FROM public.invoice GROUP BY invoice.period_to) <= '2017-10-01' OR invoice.id IS NULL) 

Aber Fehler ERROR: invalid value for logical type: "2017-10-01"

mich tun Hilfe pls

Answer 1

Vermutlich Sie wollen:

select c.id, max(i.period_to) 
from public.contract c left join 
    public.invoice 
    on i.contract_id = c.id 
where c.close_type IS NULL and c.payment_type <> 'TRIAL' 
group by c.id 
having max(i.period_to) <= '2017-10-01' OR max(i.id) IS NULL;