How to get some of the records but not all of them in a query

Question

Hi there I have a query which returns the events that do not have the mrreceived as 'Y'. Am trying to find a way how we can rewrite the query that gives the events without mrreceived as 'Y" or mrreceived as null but the events with both of the combined?
{code}
select c.client_id,
e.event_id,
e.mrreceived,
e.event_status_code,
e.proj_batch_id,
p.providername,
p.clientproviderid
from event e, client c, clientprovider p
where e.client_id = c.client_id
and e.clientproviderid = p.clientproviderid
and c.client_id = 1250
and p.clientproviderid not in
(select distinct b.clientproviderid from clientprovider b, event x
where b.clientproviderid = p.clientproviderid
and b.clientproviderid = x.clientproviderid
and x.mrreceived = 'Y'
and e.client_id = 1250)
{code}

Answer 1

user11961230 wrote:
i just want to see the id 10371.OK. So you want to see id that has both Y and NULL, right? If so:
select c.client_id,
       e.event_id,
       e.mrreceived,
       e.event_status_code,
       e.proj_batch_id,
       p.providername,
       p.clientproviderid
from   event e, client c, clientprovider p
where  e.client_id = c.client_id
and    e.clientproviderid = p.clientproviderid
and    c.client_id = 1250
and    p.clientproviderid in
       (select b.clientproviderid  from clientprovider b, event x
         where  b.clientproviderid = p.clientproviderid
         and    b.clientproviderid = x.clientproviderid
         and    (x.mrreceived = 'Y' or x.mrreceived IS NULL)
         and    e.client_id = 1250
         group by b.clientproviderid
         having count(distinct nvl(x.mrreceived,'X')) = 2
/SY.