Here's the data:
[ TABLE_1 ]
id | prod1 | date1 | prod2 | date2 | prod3 | date3 |
---|--------|--------|--------|--------|--------|-------|
1 | null | null | null | null | null | null |
2 | null | null | null | null | null | null |
3 | null | null | null | null | null | null |
[ TABLE_2 ]
id | date | product |
-----|-------------|-----------|
1 | 20140101 | X |
1 | 20140102 | Y |
1 | 20140103 | Z |
2 | 20141201 | data |
2 | 20141201 | Y |
2 | 20141201 | Z |
3 | 20150101 | data2 |
3 | 20150101 | data3 |
3 | 20160101 | X |
Both tables have other columns not listed here.
date
is formatted: yyyymmdd and datatype is int
. [ TABLE_2 ]
doesn't have empty rows, just tried to make sample above more readable.
Here's the Goal:
I need to update
[ TABLE_1 ]
prod1
,date1
,prod2
,date2
,prod3
,date3
with product
collected from [ TABLE_2 ]
with corresponding date
values.
Data must be sorted so that "latest"
product
becomes prod1
, 2nd latest product
will be prod2
and 3rd is prod3
.
Latest
product
= biggest date
(int). If dates are equal, order doesn't matter. (see id=2 and id=3).
Updated
[ TABLE_1 ]
should be:id | prod1 | date1 | prod2 | date2 | prod3 | date3 |
---|--------|----------|--------|----------|--------|----------|
1 | Z | 20140103 | Y | 20140102 | X | 20140101 |
2 | data | 20141201 | Y | 20141201 | Z | 20141201 |
3 | X | 20160101 | data2 | 20150101 | data3 | 20150101 |
Ultimate goal is to get the following :
[ TABLE_3 ]
id | order1 | order2 | order3 | + Columns from [ TABLE_1 ]
---|--------------------|----------------------|------------|--------------------------
1 | 20140103:Z | 20140102:Y | 20140103:Z |
2 | 20141201:data:Y:Z | NULL | NULL |
3 | 20160101:X | 20150101:data2:data3 | NULL |
I have to admit this exceeds my knowledge and I haven't tried anything.
Should I do it with JOIN or SELECT subquery?
Should I try to make it in one SQL -clause or perhaps in 3 steps, each
prod
&date
-pair at the time ?
What about creating
[ TABLE_3 ]
? It has to have columns from [ TABLE_1 ]
. Is it easiest to create it from [ TABLE_2 ]
-data or Updated [ TABLE_1 ]
?
Any help would be highly appreciated. Thanks in advance.
I'll post some of my own shots on comments.
After looking into it (after my comment), a stored procedure would be best, that you can call to view the data as a pivot, and do away with TABLE_1. Obviously if you need to make this dynamic, you'll need to look into dynamic pivots, it's a bit of a hack with CTEs:
CREATE PROCEDURE DBO.VIEW_AS_PIVOTED_DATA
AS
;WITH CTE AS (
SELECT ID, [DATE], 'DATE' + CAST(ROW_NUMBER() OVER(PARTITION BY ID ORDER BY [DATE] DESC) AS VARCHAR) AS [RN]
FROM TABLE_2)
, CTE2 AS (
SELECT ID, PRODUCT, 'PROD' + CAST(ROW_NUMBER() OVER(PARTITION BY ID ORDER BY [DATE] DESC) AS VARCHAR) AS [RN]
FROM TABLE_2)
, CTE3 AS (
SELECT ID, [DATE1], [DATE2], [DATE3]
FROM CTE
PIVOT(MAX([DATE]) FOR RN IN ([DATE1],[DATE2],[DATE3])) PIV)
, CTE4 AS (
SELECT ID, [PROD1], [PROD2], [PROD3]
FROM CTE2
PIVOT(MAX(PRODUCT) FOR RN IN ([PROD1],[PROD2],[PROD3])) PIV)
SELECT A.ID, [PROD1], [DATE1], [PROD2], [DATE2], [PROD3], [DATE3]
FROM CTE3 AS A
JOIN CTE4 AS B
ON A.ID=B.ID
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