Smearing start-end date data

smear.sql

Imagine you have some start-end data:

create table PRD_CAA_CRE_DDWSP_PI6_DPOL.TBL_DATA_1 as (
select ACCT_ID
		,	START_DATE
		,	END_DATE
        ,   CURR_CRDT_LIM_AMT
from PRD_ADS_IL_VR.VR_S_ACCT_CRDT_CRD_RAW
sample 1000)
with data;


Step 1: create a calendar table that has one record for every date you want:

create table PRD_CAA_CRE_DDWSP_PI6_DPOL.T_CALENDAR as
(SELECT calendar_date as DAY_VAL
FROM SYS_CALENDAR.Calendar
where calendar_date > to_date('2016-09-01')
) with data;


Step 2: do a Cartesian join to “smear” the start-end formatted data

SELECT ACCT_ID
					,  	DAY_VAL
					, 	CURR_CRDT_LIM_AMT
FROM  ( SELECT DAY_VAL FROM PRD_CAA_CRE_DDWSP_PI6_DPOL.T_CALENDAR ) A
          ,   ( SELECT ACCT_ID, CURR_CRDT_LIM_AMT, START_DATE, END_DATE
                FROM PRD_CAA_CRE_DDWSP_PI6_DPOL.TBL_DATA_1) B
WHERE DAY_VAL between START_DATE and END_DATE
-- order by ACCT_ID, DAY_VAL
;