Converting rows to column using SQL - sql

Question

I am trying to solve a problem. I want to change the rows into columns but I am not sure on how to do this. Pivot is a solution but the columns are not being fetched as I want them to. Here is an example.
The table above is the one that I want to use and convert it into something similar to the below one
Basicaly the quaters needs to be distributed in years on the same row for the same request ID. I had tried CASE but that seems to be an overkill for something like this.
Here is a fiddle to start with.
Thanks.

Answer 1

To get fully elastic solution you should search for dynamic pivot. If you know years in advance you could use:
;WITH cte AS
(
SELECT ReqId,quater1,quater2,quater3,quater4
,[q1] = CONCAT('Q1_',[year])
,[q2] = CONCAT('Q2_',[year])
,[q3] = CONCAT('Q3_',[year])
,[q4] = CONCAT('Q4_',[year])
FROM #forecast
)
SELECT ReqId
,[Q1_2014] = MAX([Q1_2014])
,[Q2_2014] = MAX([Q2_2014])
,[Q3_2014] = MAX([Q3_2014])
,[Q4_2014] = MAX([Q4_2014])
,[Q1_2015] = MAX([Q1_2015])
,[Q2_2015] = MAX([Q2_2015])
,[Q3_2015] = MAX([Q3_2015])
,[Q4_2015] = MAX([Q4_2015])
,[Q1_2016] = MAX([Q1_2016])
,[Q2_2016] = MAX([Q2_2016])
,[Q3_2016] = MAX([Q3_2016])
,[Q4_2016] = MAX([Q4_2016])
,[Q1_2017] = MAX([Q1_2017])
,[Q2_2017] = MAX([Q2_2017])
,[Q3_2017] = MAX([Q3_2017])
,[Q4_2017] = MAX([Q4_2017])
FROM cte
PIVOT (MAX(quater1) FOR [q1] IN ([Q1_2014],[Q1_2015],[Q1_2016],[Q1_2017])) AS pvt1
PIVOT (MAX(quater2) FOR [q2] IN ([Q2_2014],[Q2_2015],[Q2_2016],[Q2_2017])) AS pvt2
PIVOT (MAX(quater3) FOR [q3] IN ([Q3_2014],[Q3_2015],[Q3_2016],[Q3_2017])) AS pvt3
PIVOT (MAX(quater4) FOR [q4] IN ([Q4_2014],[Q4_2015],[Q4_2016],[Q4_2017])) AS pvt4
GROUP BY ReqId
LiveDemo
Output:
╔════════╦══════════╦══════════╦══════════╦══════════╦══════════╦══════════╦══════════╦══════════╦══════════╦══════════╦══════════╦══════════╦══════════╦══════════╦══════════╦═════════╗
║ ReqId ║ Q1_2014 ║ Q2_2014 ║ Q3_2014 ║ Q4_2014 ║ Q1_2015 ║ Q2_2015 ║ Q3_2015 ║ Q4_2015 ║ Q1_2016 ║ Q2_2016 ║ Q3_2016 ║ Q4_2016 ║ Q1_2017 ║ Q2_2017 ║ Q3_2017 ║ Q4_2017 ║
╠════════╬══════════╬══════════╬══════════╬══════════╬══════════╬══════════╬══════════╬══════════╬══════════╬══════════╬══════════╬══════════╬══════════╬══════════╬══════════╬═════════╣
║ 1 ║ 10 ║ 20 ║ 30 ║ 40 ║ 50 ║ 60 ║ 70 ║ 80 ║ 90 ║ 100 ║ 110 ║ 120 ║ (null) ║ (null) ║ (null) ║ (null) ║
║ 2 ║ 10 ║ 20 ║ 30 ║ 40 ║ 50 ║ 60 ║ 70 ║ 80 ║ 90 ║ 100 ║ 110 ║ 120 ║ 130 ║ 140 ║ 150 ║ 160 ║
╚════════╩══════════╩══════════╩══════════╩══════════╩══════════╩══════════╩══════════╩══════════╩══════════╩══════════╩══════════╩══════════╩══════════╩══════════╩══════════╩═════════╝
Addendum 1
Alternatively:
;WITH cte AS (
SELECT ReqId, [q] ='Q1_' + CAST([year] AS CHAR(4)), quater = quater1 FROM #forecast
UNION ALL SELECT ReqId, [q] ='Q2_' + CAST([year] AS CHAR(4)), quater2 FROM #forecast
UNION ALL SELECT ReqId, [q] ='Q3_' + CAST([year] AS CHAR(4)), quater3 FROM #forecast
UNION ALL SELECT ReqId, [q] ='Q4_' + CAST([year] AS CHAR(4)), quater4 FROM #forecast
)
SELECT *
FROM cte
PIVOT (MAX(quater) FOR q IN (Q1_2014,Q2_2014,Q3_2014,Q4_2014,
Q1_2015,Q2_2015,Q3_2015,Q4_2015,
Q1_2016,Q2_2016,Q3_2016,Q4_2016,
Q1_2017,Q2_2017,Q3_2017,Q4_2017)
) AS pvt;
LiveDemo2
Addendum 2
Dynamic Pivot (you don't need to know years in advance):
DECLARE #sql NVARCHAR(MAX) = N'
WITH cte AS (
SELECT ReqId,[q] =''Q1_'' + CAST([year] AS CHAR(4)),quater = quater1 FROM #forecast
UNION ALL SELECT ReqId,[q] =''Q2_'' + CAST([year] AS CHAR(4)),quater2 FROM #forecast
UNION ALL SELECT ReqId,[q] =''Q3_'' + CAST([year] AS CHAR(4)),quater3 FROM #forecast
UNION ALL SELECT ReqId,[q] =''Q4_'' + CAST([year] AS CHAR(4)),quater4 FROM #forecast
)
SELECT *
FROM cte
PIVOT (MAX(quater) FOR q IN (<placeholder>)
) AS pvt;';
DECLARE #cols NVARCHAR(MAX) =
STUFF((SELECT ',' + QUOTENAME('Q1_' + CAST([year] AS CHAR(4))) +
',' + QUOTENAME('Q2_' + CAST([year] AS CHAR(4))) +
',' + QUOTENAME('Q3_' + CAST([year] AS CHAR(4))) +
',' + QUOTENAME('Q4_' + CAST([year] AS CHAR(4)))
FROM (SELECT DISTINCT [year] FROM #forecast) cte
ORDER BY [year]
FOR XML PATH(''), TYPE).value('.', 'NVARCHAR(MAX)') , 1, 1, '');
SET #sql = REPLACE(#sql, '<placeholder>', #cols);
EXEC [dbo].[sp_executesql] #sql;
LiveDemo3

Answer 2

Look That:
Concatenate Rows
Maybe give you a way.