Select dates missing data in a range - postgresql

Question

I have a postgres table test_table that looks like this:
date | test_hour
------------+-----------
2000-01-01 | 1
2000-01-01 | 2
2000-01-01 | 3
2000-01-02 | 1
2000-01-02 | 2
2000-01-02 | 3
2000-01-02 | 4
2000-01-03 | 1
2000-01-03 | 2
I need to select all the dates which don't have test_hour = 1, 2, and 3, so it should return
date
------------
2000-01-03
Here is what I have tried:
SELECT date FROM test_table WHERE test_hour NOT IN (SELECT generate_series(1,3));
But that only returns dates that have extra hours beyond 1, 2, 3

Answer 1

You can use aggregation and conditional HAVING clauses, like so:
SELECT mydate
FROM mytable
GROUP BY mydate
HAVING
MAX(CASE WHEN test_hour = 1 THEN 1 END) != 1
OR MAX(CASE WHEN test_hour = 2 THEN 1 END) != 1
OR MAX(CASE WHEN test_hour = 3 THEN 1 END) != 1

Answer 2

Another possibility would be to join it against the series (or another subquery containing the hours) and do a [distinct] count on the hours aggregatet per date:
select date from tst
inner join (select generate_series(1,3) "hour") hours on hours.hour = tst.hour
group by tst.date
having count(distinct tst.hour) < 3;
or
select date from tst
where hour in (select generate_series(1,3))
group by date
having count(distinct tst.hour) < 3;
[You don't need the distinct if date/hour combinations in Your table are unique]

Answer 3

A solution using set difference, giving you exactly the rows that are missing:
(SELECT DISTINCT
date, all_hour
FROM test_table
CROSS JOIN generate_series(1,3) all_hour)
EXCEPT
(TABLE test_table)
And a solution using an array aggregate and the array contains operator:
SELECT date
FROM test_table
GROUP BY date
HAVING NOT array_agg(test_hour) #> ARRAY(SELECT generate_series(1,3))
(online demos)