Duplicating records to fill gap between dates in Google BigQuery

Question

So I\'ve found similar resources that address how to do this in SQL, like this: Duplicating records to fill gap between dates

I understand that BigQuery may not be t

Answer 1

I need to generate a table that has all the dates within a given range, but I'm having a hard time understanding if this can be done. Any ideas?

SELECT DATE(DATE_ADD(TIMESTAMP("2016-08-01"), pos - 1, "DAY")) AS DAY
FROM (
     SELECT ROW_NUMBER() OVER() AS pos, *
     FROM (FLATTEN((
     SELECT SPLIT(RPAD('', 1 + DATEDIFF(TIMESTAMP("2016-08-07"), TIMESTAMP("2016-08-01")), '.'),'') AS h
     FROM (SELECT NULL)),h
)))

Answer 2

How can I build a query within Google BigQuery that yields an output like the one below? A value at a given date is repeated until the next change for the dates in between

See example below

SELECT
  MODIFY_DATE, 
  MAX(SKU_TEMP) OVER(PARTITION BY grp) AS SKU,
  MAX(STORE_TEMP) OVER(PARTITION BY grp) AS STORE,
  MAX(STOCK_ON_HAND_TEMP) OVER(PARTITION BY grp) AS STOCK_ON_HAND,
FROM (
  SELECT
    DAY AS MODIFY_DATE, SKU AS SKU_TEMP, STORE AS STORE_TEMP, STOCK_ON_HAND AS STOCK_ON_HAND_TEMP,
    COUNT(SKU) OVER(ORDER BY DAY ASC ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS grp,
  FROM (
    SELECT DATE(DATE_ADD(TIMESTAMP("2016-08-01"), pos - 1, "DAY")) AS DAY
    FROM (
         SELECT ROW_NUMBER() OVER() AS pos, *
         FROM (FLATTEN((
         SELECT SPLIT(RPAD('', 1 + DATEDIFF(TIMESTAMP("2016-08-07"), TIMESTAMP("2016-08-01")), '.'),'') AS h
         FROM (SELECT NULL)),h
    )))
  ) AS DATES
  LEFT JOIN (
    SELECT DATE(MODIFY_DATE) AS MODIFY_DATE, SKU, STORE, STOCK_ON_HAND 
    FROM 
      (SELECT "2016-08-01" AS MODIFY_DATE, "1120010" AS SKU, 21 AS STORE, 75 AS STOCK_ON_HAND),
      (SELECT "2016-08-05" AS MODIFY_DATE, "1120010" AS SKU, 22 AS STORE, 100 AS STOCK_ON_HAND),
      (SELECT "2016-08-07" AS MODIFY_DATE, "1120011" AS SKU, 23 AS STORE, 40 AS STOCK_ON_HAND),
  ) AS TABLE_WITH_GAPS
  ON TABLE_WITH_GAPS.MODIFY_DATE = DATES.DAY
)
ORDER BY MODIFY_DATE