data feed for reporting table in oracle (rollup vs grouping sets)
I have a query:
select country_region,
country_subregion,
country_name,
calendar_year,
calendar_quarter_number,
sum(amount_sold) as amount
from countries co join
开发者_开发技巧 customers cu on co.country_id = cu.country_id join
sales sa on cu.cust_id = sa.cust_id join
times ti on sa.time_id = ti.time_id
where ( co.country_region = 'Americas'
or co.country_region = 'Middle East'
)
and ti.calendar_year between 2000 and 2001
group by grouping sets
(
(country_region, country_subregion, country_name, calendar_year, calendar_quarter_number),
(country_region, country_subregion, country_name, calendar_year),
(country_region, country_subregion, country_name),
(country_region, country_subregion, calendar_year, calendar_quarter_number),
(country_region, country_subregion, calendar_year),
(country_region, country_subregion),
(country_region, calendar_year, calendar_quarter_number),
(country_region, calendar_year),
(country_region),
(calendar_year, calendar_quarter_number),
(calendar_year),
()
)
order by amount desc;
What would be the query that returns the same output but uses group by rollup clause. I want to have a single query.
The equivalent query using the ROLLUP
clause, is this:
select country_region
, country_subregion
, country_name
, calendar_year
, calendar_quarter_number
, sum(amount_sold) as amount
from countries co
join customers cu on co.country_id = cu.country_id
join sales sa on cu.cust_id = sa.cust_id
join times ti on sa.time_id = ti.time_id
where ( co.country_region='Americas'
or co.country_region='Middle East'
)
and ti.calendar_year between 2000 and 2001
group by rollup (country_region, country_subregion, country_name)
, rollup (calendar_year, calendar_quarter_number)
order by amount desc
Here is the proof:
group by rollup (country_region, country_subregion, country_name)
, rollup (calendar_year, calendar_quarter_number)
equals
group by grouping sets
( (country_region, country_subregion, country_name)
, (country_region, country_subregion)
, (country_region)
, ()
)
, grouping sets
( (calendar_year, calendar_quarter_number)
, (calendar_year)
, ()
)
which equals
group by grouping sets
( (country_region, country_subregion, country_name, calendar_year, calendar_quarter_number)
, (country_region, country_subregion, country_name, calendar_year)
, (country_region, country_subregion, country_name)
, (country_region, country_subregion, calendar_year, calendar_quarter_number)
, (country_region, country_subregion, calendar_year)
, (country_region, country_subregion)
, (country_region, calendar_year, calendar_quarter_number)
, (country_region, calendar_year)
, (country_region)
, (calendar_year, calendar_quarter_number)
, (calendar_year)
, ()
)
which equals your original query.
You can find more information about the group by extensions in this article that I wrote last year: http://www.rwijk.nl/AboutOracle/All_About_Grouping.pdf
Regards, Rob.
精彩评论