Rullende 90 dages datovindue i SQL Oracle

Fra Oracle 12 er dette den slags forespørgsel, der MATCH_RECOGNIZE er beregnet til:

SELECT tran_dt,
       alert,
       tran_dt
         - LAG(CASE alert WHEN 'Yes' THEN tran_dt END, 1, tran_dt)
             IGNORE NULLS OVER (ORDER BY tran_dt)
         AS days
FROM   table_name
MATCH_RECOGNIZE (
  ORDER BY tran_dt
  MEASURES
    CLASSIFIER() AS alert
  ALL ROWS PER MATCH
  PATTERN ( "Yes" "No"* )
  DEFINE
    "No" AS tran_dt <= "Yes".tran_dt + INTERVAL '90' DAY
)

Før Oracle 12 kan du bruge en rekursiv forespørgsel:

WITH dates (tran_dt, rn) AS (
  SELECT tran_dt,
         ROW_NUMBER() OVER (ORDER BY tran_dt) AS rn
  FROM   table_name
),
rolling_dates (tran_dt, alert, rn, days, last_alert) AS (
  SELECT tran_dt, 'Yes', rn, 0, tran_dt
  FROM   dates
  WHERE  rn = 1
UNION ALL
  SELECT d.tran_dt,
         CASE
         WHEN d.tran_dt <= r.last_alert + INTERVAL '90' DAY
         THEN 'No'
         ELSE 'Yes'
         END,
         d.rn,
         d.tran_dt - r.last_alert,
         CASE
         WHEN d.tran_dt <= r.last_alert + INTERVAL '90' DAY
         THEN r.last_alert
         ELSE d.tran_dt
         END
  FROM   rolling_dates r
         INNER JOIN dates d
         ON (r.rn + 1 = d.rn)
)
SELECT tran_dt,
       alert,
       days
FROM   rolling_dates;

Begge udgange:

db<>fiddle her