12 month rolling from a entered month? - sql

Question

Hi can someone please help me, I want to create a script with a month parameter, the results I require is the next 12 month's names as column headings.
For example if the parameter is February the results should be:
March | April | May | June | July | August | September | October | November | December | January | February |
As the column names which I want to use to fill in values at a later stage.
Can someone please advise me on this and how I can achieve this
My script I have so far don't know how to approach this
declare #MonthParam varchar(20) = 'March'
declare #MonthNumber int = (
Select CASE WHEN #MonthParam = 'January' THEN 1
WHEN #MonthParam = 'February' THEN 2
WHEN #MonthParam = 'March' THEN 3
WHEN #MonthParam = 'April' THEN 4
WHEN #MonthParam = 'May' THEN 5
WHEN #MonthParam = 'June' THEN 6
WHEN #MonthParam = 'July' THEN 7
WHEN #MonthParam = 'August' THEN 8
WHEN #MonthParam = 'September' THEN 9
WHEN #MonthParam = 'October' THEN 10
WHEN #MonthParam = 'November' THEN 11
WHEN #MonthParam = 'December' THEN 12
END)
WHILE(#MonthNumber < 13)
BEGIN
declare #month varchar(20) = DateName( month , DateAdd( month , #MonthNumber , 0 ) - 1 )
declare #sql varchar(max)
set #sql = 'select val as ' + #month + ' from t'
exec (#sql)
SET #MonthNumber = #MonthNumber + 1;
END

Answer 1

Other wise you can use the "simplified" approach.
declare #MonthParam varchar(20) = 'March'
declare #Dte date = CAST(concat(#MonthParam, ' 01 1900') AS DATE)
declare #sql varchar(max) = concat('select null as ', DATENAME(MONTH, DATEADD(MONTH, 1, #Dte)),
', null as ', DATENAME(MONTH, DATEADD(MONTH, 2, #Dte)),
',null as ',DATENAME(MONTH, DATEADD(MONTH, 3, #Dte)),
',null as ',DATENAME(MONTH, DATEADD(MONTH, 4, #Dte)),
',null as ',DATENAME(MONTH, DATEADD(MONTH, 5, #Dte)),
',null as ',DATENAME(MONTH, DATEADD(MONTH, 6, #Dte)),
',null as ',DATENAME(MONTH, DATEADD(MONTH, 7, #Dte)),
',null as ',DATENAME(MONTH, DATEADD(MONTH, 8, #Dte)),
',null as ',DATENAME(MONTH, DATEADD(MONTH, 9, #Dte)),
',null as ',DATENAME(MONTH, DATEADD(MONTH, 10, #Dte)),
',null as ',DATENAME(MONTH, DATEADD(MONTH, 11, #Dte)),
',null as ',DATENAME(MONTH, DATEADD(MONTH, 12, #Dte)))
exec (#sql)

Answer 2

declare #date_entered varchar(50) = 'February'
set #date_entered = #date_entered + ' 01 ' + CONVERT(char(4),year(getdate()))
declare #start_month datetime = #date_entered
declare #loop_month datetime = #start_month
declare #sql nvarchar(max)
set #sql = 'CREATE TABLE MyDates ('
WHILE #loop_month < DATEADD(year,1,#start_month)
BEGIN
set #sql += DATENAME(month,#loop_month) + ' varchar(100),'
set #loop_month = DATEADD(month,1,#loop_month)
END
-- Get rid of the comma at the end of the string and close the table paranthesis (edit was to the following bit)
set #sql = LEFT(#sql,len(#sql)-1) + ')'
print #sql
--Uncomment below to run
--exec(#sql)

Answer 3

I've used a temp table with some dummy data to show the final output as a table
DECLARE #PivotColumnHeaders VARCHAR(MAX);
DECLARE #date_entered varchar(50) = 'February';
SET #date_entered = #date_entered + ' 01 ' + CONVERT(CHAR(4),YEAR(GETDATE()));
DECLARE #s INT= 1, #e INT = 12;
CREATE TABLE PivotTemp (Dummy INT, [MonthName] VARCHAR(15));
WHILE ( #s <= #e)
BEGIN
SELECT #PivotColumnHeaders =
COALESCE(
#PivotColumnHeaders + ',[' + DATENAME(MONTH,DATEADD(MONTH, #s, #date_entered)) + ']',
'[' + DATENAME(MONTH,DATEADD(MONTH, #s, #date_entered))+ ']'
);
INSERT INTO PivotTemp ( Dummy, [MonthName] ) VALUES ( #s, DATENAME(MONTH,DATEADD(MONTH, #s, #date_entered)) );
SET #s = #s + 1;
END;
--SELECT #PivotColumnHeaders ;
--SELECT * FROM PivotTemp ;
DECLARE #PivotTableSQL NVARCHAR(MAX);
SET #PivotTableSQL = N'
SELECT *
FROM (
SELECT
H.Dummy [DummyValue],
H.[MonthName] [MonthName]
FROM dbo.PivotTemp H
) AS PivotData
PIVOT (
MAX(DummyValue)
FOR [MonthName] IN (
' + #PivotColumnHeaders + '
)
) AS PivotTable
';
EXECUTE(#PivotTableSQL);
DROP TABLE PivotTemp;