Oracle SQL Analytic query-рекурсивная электронная таблица-как работает total
у меня есть следующие данные в составе A значение, упорядоченных по
4 ответов
Так давайте развязать MODEL предложение (устройство, тайна которого превышена только его мощностью) по этой проблеме:
with data as (
select date'2012-01-01' as mm, 800 as a from dual union all
select date'2012-02-01' as mm, 1900 as a from dual union all
select date'2012-03-01' as mm, 1750 as a from dual union all
select date'2012-04-01' as mm, -20000 as a from dual union all
select date'2012-05-01' as mm, 900 as a from dual union all
select date'2012-06-01' as mm, 3900 as a from dual union all
select date'2012-07-01' as mm, -2600 as a from dual union all
select date'2012-08-01' as mm, -2600 as a from dual union all
select date'2012-09-01' as mm, 2100 as a from dual union all
select date'2012-10-01' as mm, -2400 as a from dual union all
select date'2012-11-01' as mm, 1100 as a from dual union all
select date'2012-12-01' as mm, 1300 as a from dual
)
select mm, a, b
from (
-- Add a dummy value for b, making it available to the MODEL clause
select mm, a, 0 b
from data
)
-- Generate a ROW_NUMBER() dimension, in order to access rows by RN
model dimension by (row_number() over (order by mm) rn)
-- Spreadsheet values / measures involved in calculations are mm, a, b
measures (mm, a, b)
-- A single rule will do. Any value of B should be calculated according to
-- GREATEST([previous value of B] + [current value of A], 0)
rules (
b[any] = greatest(nvl(b[cv(rn) - 1], 0) + a[cv(rn)], 0)
)
выше урожайность:
MM A B
01.01.2012 800 800
01.02.2012 1900 2700
01.03.2012 1750 4450
01.04.2012 -20000 0
01.05.2012 900 900
01.06.2012 3900 4800
01.07.2012 -2600 2200
01.08.2012 -2600 0
01.09.2012 2100 2100
01.10.2012 -2400 0
01.11.2012 1100 1100
01.12.2012 1300 2400
Я придумал пользовательскую агрегатную функцию
create or replace type tsum1 as object
(
total number,
static function ODCIAggregateInitialize(nctx IN OUT tsum1 )
return number,
member function ODCIAggregateIterate(self IN OUT tsum1 ,
value IN number )
return number,
member function ODCIAggregateTerminate(self IN tsum1,
retVal OUT number,
flags IN number)
return number,
member function ODCIAggregateMerge(self IN OUT tsum1,
ctx2 IN tsum1)
return number
)
/
create or replace type body tsum1
is
static function ODCIAggregateInitialize(nctx IN OUT tsum1)
return number
is
begin
nctx := tsum1(0);
return ODCIConst.Success;
end;
member function ODCIAggregateIterate(self IN OUT tsum1,
value IN number )
return number
is
begin
self.total := self.total + value;
if (self.total < 0) then
self.total := 0;
end if;
return ODCIConst.Success;
end;
member function ODCIAggregateTerminate(self IN tsum1,
retVal OUT number,
flags IN number)
return number
is
begin
retVal := self.total;
return ODCIConst.Success;
end;
member function ODCIAggregateMerge(self IN OUT tsum1,
ctx2 IN tsum1)
return number
is
begin
self.total := self.total + ctx2.total;
return ODCIConst.Success;
end;
end;
/
CREATE OR REPLACE FUNCTION sum1(input number)
RETURN number
PARALLEL_ENABLE AGGREGATE USING tsum1;
/
запрос
with T1 as(
select date'2012-01-01' as mm, 800 as a from dual union all
select date'2012-02-01' as mm, 1900 as a from dual union all
select date'2012-03-01' as mm, 1750 as a from dual union all
select date'2012-04-01' as mm, -20000 as a from dual union all
select date'2012-05-01' as mm, 900 as a from dual union all
select date'2012-06-01' as mm, 3900 as a from dual union all
select date'2012-07-01' as mm, -2600 as a from dual union all
select date'2012-08-01' as mm, -2600 as a from dual union all
select date'2012-09-01' as mm, 2100 as a from dual union all
select date'2012-10-01' as mm, -2400 as a from dual union all
select date'2012-11-01' as mm, 1100 as a from dual union all
select date'2012-12-01' as mm, 1300 as a from dual
)
select mm
, a
, sum1(a) over(order by mm) as b
from t1
Mm a b
----------------------------
01.01.2012 800 800
01.02.2012 1900 2700
01.03.2012 1750 4450
01.04.2012 -20000 0
01.05.2012 900 900
01.06.2012 3900 4800
01.07.2012 -2600 2200
01.08.2012 -2600 0
01.09.2012 2100 2100
01.10.2012 -2400 0
01.11.2012 1100 1100
01.12.2012 1300 2400
with sample_data as (
select date'2012-01-01' as mm, 800 as a from dual union all
select date'2012-02-01' as mm, 1900 as a from dual union all
select date'2012-03-01' as mm, 1750 as a from dual union all
select date'2012-04-01' as mm, -20000 as a from dual union all
select date'2012-05-01' as mm, 900 as a from dual union all
select date'2012-06-01' as mm, 3900 as a from dual union all
select date'2012-07-01' as mm, -2600 as a from dual union all
select date'2012-08-01' as mm, -2600 as a from dual union all
select date'2012-09-01' as mm, 2100 as a from dual union all
select date'2012-10-01' as mm, -2400 as a from dual union all
select date'2012-11-01' as mm, 1100 as a from dual union all
select date'2012-12-01' as mm, 1300 as a from dual
)
select mm,
a,
greatest(nvl(a,0) + lag(a,1,0) over (order by mm), 0) as b
from sample_data;
тем не менее не произвести эту строку:
2012-05-01 | 900 | 900
потому что он вычисляет 900 - 20000 в эту строку, и ноль больше, чем результат. Вы можете "исправить" это, если используете
Извините, если это не по теме, учитывая версию вопроса Oracle, но теперь мы можем использовать предложение SQL: 2016 MATCH_RECOGNIZE:
select * from t
match_recognize(
order by mm
measures case classifier() when 'POS' then sum(a) else 0 end as b
all rows per match
pattern (pos* neg{0,1})
define pos as sum(a) > 0
);