问题
In this answer (with all executable simplified and documented sample code + helpful comments)
I did a kind of a trick there to calculate the last two rows of the following table:
DESCR SUM
---------------------------------- ----------
money available in 2013 33233235.3
money spent in 2013 4253235.3
money bound to contracts in 2013 34333500
money spent 2013 in % of available 12
money bound 2013 in % of available 103
Does anybody know of a better (performance, amount of code, understandability) way to do these kind of operations?
(Than to use the applied "provide unioned null row, fill with case and product()-over() on n+1 aggregation level-trick", let's call it punurofiwicapoonalt-trick (naah ... still to complicated) ... sounds like - yeah - let's call it just porno-trick ;O) (... okay ... alias capoon-trick if you do not like it))
回答1:
Thanks to the MODEL
syntax feature hint from GregV in the Oracle forum I could write this query really very short and precise without the need for porno. Cool!
So to easily check out the difference with my sample code and an at least 10g Oracle db you just need to modify the original script linked above the following way:
/**************************
* the original sample query base data
***************************/
... -- all content before the last select of the original example-SQL
/**************************
* the original sample porno-query
***************************/
,agg_porno as (
select
descr,
... -- all the porno-query details
from sum_data_lvl1
/*
DESCR SUM AGG_LVL SUM_ID
---------------------------------- ---------- ------- ------
money available in 2013 33233235.3 1 MA
money spent in 2013 4253235.3 1 MS
money bound to contracts in 2013 34333500 1 MB
money spent 2013 in % of available 12 2 MSP
money bound 2013 in % of available 103 2 MBP
*/
)
/**************************
* the new nice model-based query instead
***************************/
,agg_model as (
select
descr,
trunc(s,1) as sum,
agg_lvl,
sum_id
from sum_data_lvl1
model
dimension by (sum_id)
measures (descr, sum as s, agg_lvl)
rules (
s['MSP'] = s['MS'] / s['MA'] * 100,
s['MBP'] = s['MB'] / s['MA'] * 100
)
)
/*
DESCR SUM AGG_LVL SUM_ID
---------------------------------- ---------- ------- ------
money available in 2013 33233235.3 1 MA
money spent in 2013 4253235.3 1 MS
money bound to contracts in 2013 34333500 1 MB
money spent 2013 in % of available 12.7 2 MSP
money bound 2013 in % of available 103.3 2 MBP
*/
select * from agg_porno where 1=0 -- change to 1=1 to see these results
union all select * from agg_model where 1=1 -- change to 1=0 to hide these results
来源:https://stackoverflow.com/questions/21940392/how-to-best-calculate-n-level-aggregation-data-based-on-n-1-level-data-oracle