Question

I’m unable to take the 12 months back from current date in a SQL statement to use with my Stimulsoft report. The sql table structure is this (figure 1), note that im brazilian so the culture is set to pt-BR (dd/mm/yyyy)

this is the SQL table

http://img534.imageshack.us/img534/1093/clipboard02xva.jpg

I want to make this, the current date for the last 12 months is 01/02/2013 so we take:

| DACP_Id | FEB 2012 | MAR 2012 | ABR 2012 ... | FEB 2013

… and all the months heading back to february 2013. The rows inside the months in the pivot table are the DACP_Value in the current month.

I’m new to SQL so I hope you can help 🙂 Thanks.

Answer 1

I would be inclined not to use a dynamic pivot, and to handle the headers in your application code:

WITH Data AS
(   SELECT  DACP_ID,
            DACP_Value,
            [MonthNum] = 12 - DATEDIFF(MONTH, DACP_Date, CURRENT_TIMESTAMP)
    FROM    T
    WHERE   DATEDIFF(MONTH, DACP_Date, CURRENT_TIMESTAMP) BETWEEN 0 AND 12
)   
SELECT  *
FROM    Data
        PIVOT
        (   SUM(DACP_Value)
            FOR MonthNum IN ([0], [1], [2], [3], [4], [5], [6], [7], [8], [9], [10], [11], [12])
        ) pvt;

If you really need the Columns headers as they are then use:

DECLARE @Col NVARCHAR(MAX) = 
    (   SELECT  ', ' + QUOTENAME(CONVERT(VARCHAR, DATEADD(MONTH, DATEDIFF(MONTH, 0, CURRENT_TIMESTAMP) - (12 - Number), 0), 112)) + ' = [' + CAST(number AS VARCHAR) + ']'
        FROM    Master..spt_values
        WHERE   Type = 'P'
        AND     number BETWEEN 0 AND 12
        FOR XML PATH(''), TYPE
    ).value('.', 'NVARCHAR(MAX)');


DECLARE @SQL NVARCHAR(MAX) = 
        N'WITH Data AS
        (   SELECT  DACP_ID,
                    DACP_Value,
                    [MonthNum] = 12 - DATEDIFF(MONTH, DACP_Date, CURRENT_TIMESTAMP)
            FROM    T
            WHERE   DATEDIFF(MONTH, DACP_Date, CURRENT_TIMESTAMP) BETWEEN 0 AND 12
        )   
        SELECT  DACP_ID' + @Col + '
        FROM    Data
                PIVOT
                (   SUM(DACP_Value)
                    FOR MonthNum IN ([0], [1], [2], [3], [4], [5], [6], [7], [8], [9], [10], [11], [12])
                ) pvt;';

EXECUTE SP_EXECUTESQL @SQL;

You can change the value 112 when converting a date to a varchar to various numbers to change the format of your date in the column headers (103 will give you dd/mm/yyyy as stated in the question).

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SQL Fiddle (Shamelessly stolen from @bluefeet, who beat me to the answer). I’ve left this answer here though as it is slightly different as it will provide 13 columns (for the last year and current month) whether or not data exists for that month in the table.