Som ett alternativ till rekursiv SQL kan du också använda SQL MODEL klausul. Personligen tycker jag att detta är lite lättare att läsa än rekursiv SQL, även om det är svårare att skriva (eftersom de flesta, som jag, behöver slå upp syntaxen).
-- "test_data" is just a substitute for your real table, which I don't have
-- it is just so people without your table can run this example and would
-- not be part of your real solution.
with test_data ( sort_col, addend ) as
( SELECT 'A', 3 FROM DUAL UNION ALL
SELECT 'B', 7 FROM DUAL UNION ALL
SELECT 'C', 6 FROM DUAL UNION ALL
SELECT 'D', 5 FROM DUAL UNION ALL
SELECT 'E', 9 FROM DUAL UNION ALL
SELECT 'F', 3 FROM DUAL UNION ALL
SELECT 'G', 8 FROM DUAL ),
-- Solution begins here
sorted_inputs ( sort_col, sort_order, addend, running_sum_max_15) as
( SELECT sort_col, row_number() over ( order by sort_col ) sort_order, addend, 0 from test_data )
SELECT sort_col, addend, running_sum_max_15
from sorted_inputs
model
dimension by (sort_order)
measures ( sort_col, addend, running_sum_max_15 )
rules update
( running_sum_max_15[1] = addend[1],
running_sum_max_15[sort_order>1] =
case when running_sum_max_15[CV(sort_order)-1] < 15 THEN
running_sum_max_15[CV(sort_order)-1] ELSE 0 END+addend[CV(sort_order)]
)
RESULTAT
+----------+--------+--------------------+
| SORT_COL | ADDEND | RUNNING_SUM_MAX_15 |
+----------+--------+--------------------+
| A | 3 | 3 |
| B | 7 | 10 |
| C | 6 | 16 |
| D | 5 | 5 |
| E | 9 | 14 |
| F | 3 | 17 |
| G | 8 | 8 |
+----------+--------+--------------------+