Równoważnik PostgreSQL dla grupy SQL Server GROUP BY WITH ROLLUP

Question

Mam kwerendę serwera SQL, który używa klauzuli ROLLUP podczas grupowania. Chcę równoważne zapytanie w Postgres. Zapytań w SQL Server jest:

SELECT (CASE WHEN acnt_dba_name Is Null THEN 'Total' ELSE acnt_dba_name END) as account, 
     (CASE WHEN evt_name Is Null THEN '' ELSE evt_name END) as event, 
     COUNT(CASE reg_is_complete WHEN true THEN 1 ELSE Null END) as regsComplete, 
     COUNT(CASE WHEN reg_frn_pro_id > 0 AND reg_is_complete = false THEN 1 ELSE Null END) as regsInComplete, 
     COUNT(CASE WHEN reg_frn_pro_id > 0 THEN Null ELSE 1 END) as regsClicks 
FROM  registrations_view 
LEFT JOIN events ON (evt_id = reg_frn_evt_id) 
LEFT JOIN accounts ON (acnt_id = evt_frn_acnt_id) 
WHERE reg_date_created < #CreateODBCDate(url.endDate)# 
AND reg_date_created > #CreateODBCDate(url.startDate)# 
AND reg_is_active = true  -- only active regs 
AND reg_is_test = false  -- only live registrations 
-- AND reg_is_denied = false   -- exclude denied reg statuses (include these for now RWB 8/7/2) 
GROUP BY rollup(acnt_dba_name, evt_name) 
-- Sort with Nulls at the bottom 
ORDER BY acnt_dba_name, evt_name 

Answer 1

with detail as (
    select 
     acnt_dba_name as account, 
     evt_name as event, 
     count(case reg_is_complete when true then 1 else null end) as regscomplete, 
     count(case when reg_frn_pro_id > 0 and reg_is_complete = false then 1 else null end) as regsincomplete, 
     count(case when reg_frn_pro_id > 0 then null else 1 end) as regsclicks 
    from 
     registrations_view 
     left join 
     events on evt_id = reg_frn_evt_id 
     left join 
     accounts on acnt_id = evt_frn_acnt_id 
    where 
     reg_date_created < #CreateODBCDate(url.endDate)# 
     AND reg_date_created > #CreateODBCDate(url.startDate)# 
     and reg_is_active = true  -- only active regs 
     and reg_is_test = false  -- only live registrations 
    group by acnt_dba_name, evt_name 
), account as (
    select 
     account, 
     '' as event, 
     sum(regscomplete) as regscomplete, 
     sum(regsimcomplete) as regsincomplete, 
     sum(regsclicks) as regsclicks 
    from detail 
    group by account 
), total as (
    select 
     'Total' as account, 
     '' as event, 
     sum(regsComplete) as regsComplete, 
     sum(regsImComplete) as regsInComplete, 
     sum(regsClicks) as regsClicks 
    from account 
) 
select * from detail 
union 
select * from account 
union 
select * from total 
order by account, event 

Answer 2

Jest to ogólny odpowiedź do równowartości roll up w PostgreSQL.

Biorąc pod stół t:

create table t (l1 char(1), l2 char(1), i integer); 
insert into t (l1, l2, i) values 
('A', 'X', 1), 
('A', 'Y', 2), 
('B', 'X', 3), 
('B', 'Y', 4); 

I to zapytanie SQL Server: SQL Fiddle

select l1, l2, sum(i) total 
from t 
group by rollup(l1, l2) 

To jak to zrobić w PostgreSQL: SQL Fiddle

Tworzenie agregacji współczynniki CTE począwszy od szczegóły przechodzenia na najwyższy poziom:

with detail as (
    select l1, l2, sum(i) total 
    from t 
    group by l1, l2 
), l2 as (
    select l1, sum(total) total 
    from detail 
    group by l1 
), l1 as (
    select sum(total) total 
    from l2 
) 

Zauważ, że dla wydajności następny wyższy poziom agreguje od poprzedniego niższego poziomu.

Z tego zrobić tylko Unii w CTE tworzenie odpowiednich etykiet:

select l1, l2, total 
from detail 
union 
select l1, 'Total', total 
from l2 
union 
select 'Total', '', total 
from l1 
order by l1, l2 

Answer 3

W PostgreSQL 9.5 pojawił grupowanie zestawów, kostka i ROLLUP: http://www.postgresql.org/docs/9.5/static/queries-table-expressions.html#QUERIES-GROUPING-SETS