The source is a rating table which contains rating and rating date for an organization. Sample data is as below
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In the target we have rating table which must have organization, ratings, rating date as a single record (i.e converting rows to columns ). Target looks like below
Below is the SQL Analytic query used
SELECT RATED_ASSESSABLE_OBJECT_ID,
rate1,
date1,
rate2,
date2,
rate3,
date3,
rate4,
date4
FROM (SELECT RATED_ASSESSABLE_OBJECT_ID as RATED_ASSESSABLE_OBJECT_ID,
rating_sYMBOL_CODE AS RATE1,
LEAD(rating_sYMBOL_CODE,1) OVER (PARTITION BY RATED_ASSESSABLE_OBJECT_ID ORDER BY RATING_EFFECTIVE_DATE) AS rate2,
LEAD(rating_sYMBOL_CODE,2) OVER (PARTITION BY RATED_ASSESSABLE_OBJECT_ID ORDER BY RATING_EFFECTIVE_DATE) AS rate3,
LEAD(rating_sYMBOL_CODE,3) OVER (PARTITION BY RATED_ASSESSABLE_OBJECT_ID ORDER BY RATING_EFFECTIVE_DATE) AS rate4,
RATING_EFFECTIVE_DATE AS daTE1,
LEAD(RATING_EFFECTIVE_DATE,1) OVER (PARTITION BY RATED_ASSESSABLE_OBJECT_ID ORDER BY RATING_EFFECTIVE_DATE) AS DATE2,
LEAD(RATING_EFFECTIVE_DATE,2) OVER (PARTITION BY RATED_ASSESSABLE_OBJECT_ID ORDER BY RATING_EFFECTIVE_DATE) AS Date3,
LEAD(RATING_EFFECTIVE_DATE,3) OVER (PARTITION BY RATED_ASSESSABLE_OBJECT_ID ORDER BY RATING_EFFECTIVE_DATE) AS Date4,
ROW_NUMBER() OVER(PARTITION BY RATED_ASSESSABLE_OBJECT_ID ORDER BY RATING_EFFECTIVE_DATE) AS ROW_NUMBER
FROM DERIVED_RATING_EVENT)
WHERE ROW_NUMBER = 1
ORDER BY RATED_ASSESSABLE_OBJECT_ID
Can this be done with JOINs functions? It's something I've been working on mastering in my academy.vertabelo.com basic SQL course, so I cannot really understand the mothod given here yet, but at least I can grasp the problem...
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