How to set the first column value of a GROUPING SETS

I have the following request :

SELECT column1, column2, SUM(column3) as total
FROM my_table
GROUP BY GROUPING SETS ((column1, column2), ())

Which returns :

So |None|None|30 is the output from the GROUPING BY SETS

But I am wondering how to define the first None to be something else :

|SubTotal|None|30

For example.

The final output would be :

>Solution :

The dialect is not provided, but the corresponding part to GROUPING SETS is GROUPING function:

Describes which of a list of expressions are grouped in a row produced by a GROUP BY query.

GROUPING_ID is not an aggregate function, but rather a utility function that can be used alongside aggregation, to determine the level of aggregation a row was generated for

CREATE TABLE my_table(Name1 TEXT, Name2 TEXT,  QTT INT)
AS    SELECT 'AB','CD',15
UNION SELECT 'ZE','EF',15;

SELECT CASE WHEN GROUPING_ID(Name1,Name2)=3THEN 'Subtotal' ELSE Name1 END AS Name1
     ,Name2, SUM(QTT) as total
FROM my_table
GROUP BY GROUPING SETS ((Name1, Name2), ());

Output:

Related:

• SQL Server GROUPING_ID
• Postgresql GROUPING
• MySQL GROUPING