SQL Server query to get date and naming columns by years - sql-server

Question

I want my query to get the years and add it without me to added manually each year such as my below query.
Note that each columns should be named as it's years
USE [My_Table]
GO
DECLARE #max_intyear INT = 0 , #max_byteQuarter INT = 0
SELECT #max_intyear = MAX(intyear), #max_byteQuarter = MAX(byteQuarter)
FROM [My_Table].[dbo].[PW_Projected]
BEGIN
SELECT
intMedicine, intForm,
MAX(CASE WHEN intyear = #max_intyear and byteQuarter = #max_byteQuarter THEN curprice END) AS curprice,
MAX(CASE WHEN byteQuarter = 1 AND intYear = 2016 THEN [curUnits] END) AS '2016_Units(ID) Q1' ,
MAX(CASE WHEN byteQuarter = 2 AND intYear = 2016 THEN [curUnits] END) AS '2016_Units(ID) Q2',
MAX(CASE WHEN byteQuarter = 3 AND intYear = 2016 THEN [curUnits] END) AS '2016_Units(ID) Q3',
MAX(CASE WHEN byteQuarter = 4 AND intYear = 2016 THEN [curUnits] END) AS '2016_Units(ID) Q4',
MAX(CASE WHEN byteQuarter = 1 AND intYear = 2017 THEN [curUnits] END) AS '2017_Units(ID) Q1' ,
MAX(CASE WHEN byteQuarter = 2 AND intYear = 2017 THEN [curUnits] END) AS '2017_Units(ID) Q2',
MAX(CASE WHEN byteQuarter = 3 AND intYear = 2017 THEN [curUnits] END) AS '2017_Units(ID) Q3',
MAX(CASE WHEN byteQuarter = 4 AND intYear = 2017 THEN [curUnits] END) AS '2017_Units(ID) Q4'
INTO
Test
--intYear
FROM
dbo.PW_Projected
WHERE
intYear >= 2016
GROUP BY
intMedicine, intForm
END

Answer 1

You can generate dynamic sql, store it in a string variable (e.g. #SQL) and run it with sp_executesql #SQL.
Dynamic sql query could look like this (syntax errors could possibly occur, I didn't run it in SSMS):
declare #sql nvarchar(max) = N''
declare #YearQuarterSelection nvarchar(max) = N''
declare #YearQuarterTable table (
y int
, q int
)
-- get all years and quarters
insert into #YearQuarterTable (
y
, q
)
select
y = intYear
, q = byteQuarter
from dbo.PW_Projected
group by intYear, byteQuarter
-- generate "case when" conditions
select #YearQuarterSelection = N' MAX(CASE WHEN byteQuarter = ' +
cast (q as nvarchar(1)) +
N' AND intYear = ' +
cast (y as nvarchar(4))
N' THEN [curUnits] END) AS ''' +
cast (y as nvarchar(4)) +
N'_Units(ID) Q' +
cast (q as nvarchar(1)) +
N''','
from YearQuarterSelection
-- remove last comma
select #YearQuarterSelection = left(YearQuarterSelection, len(YearQuarterSelection) - 1)
-- build dynamic query
select #sql = N'SELECT intMedicine, intForm, MAX(CASE WHEN intyear = ' +
cast(#max_intyear as nvarchar(4)) +
N' and byteQuarter = ' +
cast(#max_byteQuarters nvarchar(1)) +
N' THEN curprice END) AS curprice, ' +
#YearQuarterSelection +
N'INTO
Test
--intYear
FROM
dbo.PW_Projected
WHERE
intYear >= 2016
GROUP BY
intMedicine, intForm'
-- run dynamic query
exec sp_executesql #sql
Best regards, Stephan