SQL Pivot and Distinct from new Columns - sql

Question

I have a table called ADMIN that originally looks like this
KEY VALUE
Version1 2019_RQK#2019
Version2 2019_RQK#2020
Version2 2019_RQK#2021
Version2 2019_RQK#2022
Version2 2020_TKA#2020
Version2 2020_TKA#2021
Version2 2020_TKA#2022
Version2 2020_TKA#2023
And I am try to change it to look like this
VERSION YEAR1 YEAR2 YEAR3 YEAR4
2019_RQK 2019 2020 2021 2022
2020_TKA 2020 2021 2022 2023
I wrote some SQL in order to get the left and right versions of the [VALUE] columns but I dont know how to condense it so that it only shows a DISTINCT as for the left side of the [VALUE] column. I tried to use distinct but it still brings up the same repeated entries, this is what I've written so far, I dont know if PIVOT function would work here I tried a few things it didn't end up correct.
SELECT DISTINCT LEFT([VALUE], 7) AS VERSION, RIGHT([VALUE], 4) AS YEAR
FROM ADMIN
WHERE [KEY] LIKE '%VERSION%'
Just gives me, not sure how to change it in the same query
VERSION YEAR
2019_RQK 2019
2019_RQK 2020
2019_RQK 2021
2019_RQK 2022
2020_TKA 2020
2020_TKA 2021
2020_TKA 2022
2020_TKA 2023

Answer 1

So, yes, you need a PIVOT table to do that. You can learn all about them here, which has a pretty straightforward (and quick!) walkthrough to understand why it works magic.
To PIVOT this table, we need to add a column for YEAR1, YEAR2, etc.. so they can be our headers/new columns. I'll do that with a basic ROW_NUMBER function. I know this example has 4 maximum new columns per entry, so I'm hardcoding them in, but the link above explains how you can dynamically generate the IN statement if you have an unknown number of maximum columns.
Please note, my test table was created with col1 and col2 because I am lazy. You should swap those for the actual column names.
SELECT * FROM (
-- we start with your basic table, as you provided
SELECT
LEFT(col2, 7) AS VERSION,
RIGHT(col2, 4) AS YEAR,
ROW_NUMBER() OVER (partition by LEFT(col2, 7) order by RIGHT(col2, 4)) as YearNum /* sort these by the proper year, so we don't get of order */
FROM ADMIN
WHERE col1 LIKE '%VERSION%'
) versionResults
PIVOT (
max([YEAR]) -- grab the year
for [YearNum] -- this column holds our new column headers
in ( /* these are the possible YearNum values, now our new column headers */
[1],
[2],
[3],
[4]
)
) as pivotResults
Demo here.

Answer 2

You need to also extract the first 4 chars as the "base year", then subtract the "Year" from the "Base Year" (and add 1) to get an integer value (1-4) and use those as the PIVOT list.
Example Fiddle
The reason this is "difficult" is that you have 3 key values stored in 1 column. At least it's fixed width so easy enough to break apart consistently.
If the VALUE column contains differently formatted data, this won't work.
CREATE TABLE Admin
( Key1 char(8)
, Val char(13)
);
INSERT INTO Admin (Key1, Val)
VALUES
('Version1','2019_RQK#2019')
, ('Version2','2019_RQK#2020')
, ('Version2','2019_RQK#2021')
, ('Version2','2019_RQK#2022')
, ('Version2','2020_TKA#2020')
, ('Version2','2020_TKA#2021')
, ('Version2','2020_TKA#2022')
, ('Version2','2020_TKA#2023');
WITH Src AS (
SELECT
Version = SUBSTRING(Val,1,8)
, Year = CAST(SUBSTRING(Val,10,4) as int)
, YearCt = CAST(SUBSTRING(Val,10,4) as int) - CAST(SUBSTRING(Val,1,4) as int) + 1
FROM Admin
)
SELECT
pvt.Version
, Year1 = pvt.[1]
, Year2 = pvt.[2]
, Year3 = pvt.[3]
, Year4 = pvt.[4]
FROM Src
PIVOT (MAX(Year) FOR YearCt IN ([1],[2],[3],[4])) pvt;

Answer 3

Using dynamical pivoting such as below one would be a better option in terms of picking the currently inserted years with no applying any manipulation to the query while the data change
DECLARE #cols AS NVARCHAR(MAX), #query AS NVARCHAR(MAX)
SET #cols = ( SELECT STRING_AGG(CONCAT('[year',[n],']'),',')
FROM (SELECT DISTINCT
ROW_NUMBER() OVER
(PARTITION BY LEFT([value], 7) ORDER BY [value]) AS [n]
FROM [admin] ) q );
SET #query =
N'SELECT *
FROM
(
SELECT DISTINCT LEFT([value], 7) AS version, RIGHT([value], 4) AS year,
CONCAT(''year'',ROW_NUMBER() OVER
(PARTITION BY LEFT([value], 7)
ORDER BY RIGHT([value], 4))) AS [n]
FROM [admin]
WHERE [key] LIKE ''%VERSION%'' ) q
PIVOT (
MAX([year]) FOR [n] IN (' + #cols + N')
) p
ORDER BY [version]';
EXEC sp_executesql #query;
Demo
Btw, you might also split the value by # sign SUBSTRING([value],1,CHARINDEX('#',[value])-1) in order to extract version, and SUBSTRING([value],CHARINDEX('#',[value])+1,LEN([value])) in order to extract year columns without specifying the length values as arguments within the functions as an alternative.