SQL - Using CUBE grand total per row - sql

Question

Here is my code:
SELECT
ISNULL (CONVERT(VARCHAR, MONTH(PurchaseDate)), NULL) [Month],
ISNULL (Brand, CASE
WHEN MONTH(PurchaseDate) IS NOT NULL THEN 'Monthly SubTotal'
WHEN Brand IS NULL THEN 'Grand Total'
ELSE 'N/A'
END) [Brand], SUM(Price) [Total Amount]
FROM
[dbo].[Purchase_Items]
GROUP BY
MONTH(PurchaseDate), Brand WITH CUBE
I want to change it to Grand Total on selected box. How to code it or change the string on it.

Answer 1

If you first get your data (a simpler version of what you have above) you can then use that as a data source to do conversions/updates as needed.
I'm using a CTE here, but you can do it with subqueries just as well.
WITH MonthTotals AS
(SELECT
MONTH(PurchaseDate) [Month],
[Brand],
SUM(Price) [Total Amount]
FROM [dbo].[Purchase_Items]
GROUP BY MONTH(PurchaseDate), Brand WITH CUBE
)
SELECT CONVERT(VARCHAR(2), mt.[Month]) AS [Month],
CASE WHEN mt.[Month] IS NULL AND mt.[Brand] IS NULL THEN 'Grand Total'
WHEN mt.[Month] IS NULL THEN 'Grand total for ' + mt.[Brand]
WHEN mt.[Brand] IS NULL THEN 'Monthly total'
ELSE mt.[Brand] END AS [Brand]
[Total Amount]
FROM MonthTotals mt;
Note though that CUBE is usually done in SQL Server like the following - it means you can select which columns you CUBE by (or rollup, etc)
GROUP BY CUBE(MONTH(PurchaseDate), Brand)
IMPORTANT UPDATE following #MartinSmith's comment below
Martin Smith gave the advice that I should use the GROUPING function. In reviewing that function, he is 100% correct (and thankyou Martin - this is my learning for today).
For reference, the GROUPING function indicates (with a 1 or 0) whether the row is an aggregate row or not (e.g., one of the rows added by ROLLUP/CUBE/GROUPING SETs).
I also made a mistake with subtotals for months - put it in the wrong column.
Therefore, the update should be the following (note also that I have included the 'original' vales from the CUBE for month and brand as well)
WITH MonthTotals AS
(SELECT
MONTH(PurchaseDate) [Month],
[Brand],
SUM(Price) [Total Amount],
GROUPING(MONTH(PurchaseDate)) AS Agg_flag_Month,
GROUPING([Brand]) AS Agg_flag_Brand
FROM [dbo].[Purchase_Items]
GROUP BY CUBE(MONTH(PurchaseDate), Brand)
)
SELECT [Month] AS Orig_Month,
[Brand] AS Orig_Brand,
CASE WHEN Agg_flag_Month = 1 THEN 'Grand total for ' + mt.[Brand]
ELSE CONVERT(VARCHAR(2), mt.[Month])
END AS [Month],
CASE WHEN Agg_flag_Month * Agg_flag_Brand = 1 THEN 'Grand Total'
WHEN Agg_flag_Brand = 1 THEN 'Monthly total'
ELSE mt.[Brand]
END AS [Brand],
[Total Amount]
FROM MonthTotals mt;