2 Level pivot using Postgresql - postgresql

Question

I have a table whose schema along with data (table_name : raw_data) appears to be this :
name | category | clear_date |
A | GOOD | 2020-05-30 |
A | GOOD | 2020-05-30 |
A | GOOD | 2020-05-30 |
A | GOOD | 2020-05-30 |
A | BAD | 2020-05-30 |
A | BAD | 2020-05-30 |
Now if I perform a "groupby" operation using the following statement :
SELECT name, category, date(clear_date), count(clear_date)
FROM raw_data
GROUP BY name, category, date(clear_date)
ORDER BY name
I get the following answer :
name | caetgory | date | count |
A | GOOD |2020-05-30 | 4 |
A | BAD |2020-05-30 | 1 |
A | BAD |2020-05-31 | 1 |
IN order to produce the pivot in following format :
name | category | 2020-05-30 | 2020-05-31 |
A | GOOD | 4 | NULL |
A | BAD | 1 | 1 |
I am using the following query :
select * from crosstab (
'select name, category, date(clear_date), count(clear_date) from raw_data group by name, category, date(clear_date) order by 1,2,3',
'select distinct date(clear_date) from raw_data order by 1'
)
as newtable (
node_name varchar, alarm_name varchar, "2020-05-30" integer, "2020-05-31" integer
)
ORDER BY name
But I am getting results as follows :
name | category | 2020-05-30 | 2020-05-31 |
A | BAD | 4 | 1 |
Can anyone please try to suggest how can i achieve the result mentioned above. It appears crosstab removes the duplicate entry of A automatically.

Answer 1

Not sure if this is possible using crosstab because you have a missing records in some dates. Here is an example how to get expected result but not sure is what you need. Anyway hope this helps.
SELECT r1.*, r2.counter AS "2020-05-30", r3.counter AS "2020-05-31"
FROM (
SELECT DISTINCT name, category
FROM raw_data
) AS r1
LEFT JOIN (
SELECT name, category, count(*) AS counter
FROM raw_data
WHERE clear_date = '2020-05-30'
GROUP BY name, category
) AS r2 ON (r2.category = r1.category AND r2.name = r1.name)
LEFT JOIN (
SELECT name, category, count(*) AS counter
FROM raw_data
WHERE clear_date = '2020-05-31'
GROUP BY name, category
) AS r3 ON (r3.category = r1.category AND r3.name = r1.name)
ORDER BY r1.category DESC;