Select a row when data is missing - postgresql

Question

i got a question.
I use this straight foreward query to retrieve data on a daily basis. part of the data is an ID.
For example, i got ID's 001 002 003 and 004. Every ID has some columns with data.
I daily generate a report based on that data.
A typical day looks lke
ID Date Value
001 2013-07-02 900
002 2013-07-02 800
003 2013-07-02 750
004 2013-07-02 950
Select *
FROM
myTable
WHERE datum > now() - INTERVAL '2 days' and ht not in (select ht from blocked_ht)
order by ht, id;
Some times the import for 1 id fails. So my data looks like
ID Date Value
001 2013-07-02 900
003 2013-07-02 750
004 2013-07-02 950
Its vital to know that 1 ID is missing, visualized in my report (made in Japserreports)
So i instert an ID without a date and value 0 and eddited the query:
SELECT *
FROM
"lptv_import" lptv_import
WHERE datum > now() - INTERVAL '2 days' and ht not in (select ht from negeren_ht) OR datum IS NULL
order by ht, id;
Now the data looks like this:
001 2013-07-02 900
002 800
003 2013-07-02 750
004 2013-07-02 950
How can i select from the tabel the row without the date WHEN ID 002 WITH a date is missing?
Hmm, this looks more compliacted than i thought...

Answer 1

select
id, coalesce(datum::text, 'NULL') as "date", "value"
from
(
select distinct id
from lptv
) id
left join
lptv using (id)
where
datum > now() - INTERVAL '2 days'
and not exists (select ht from negeren_ht where ht = lptv.ht)
order by id