GROUPING (Transact-SQL)

<column_expression>

Is a column or an expression that contains a column in a GROUP BY clause.

tinyint

GROUPING is used to distinguish the null values that are returned by ROLLUP, CUBE or GROUPING SETS from standard null values. The NULL returned as the result of a ROLLUP, CUBE or GROUPING SETS operation is a special use of NULL. This acts as a column placeholder in the result set and means all.

The following example groups SalesQuota and aggregates SaleYTD amounts. The GROUPING function is applied to the SalesQuota column.

USE AdventureWorks2012;
GO
SELECT SalesQuota, SUM(SalesYTD) 'TotalSalesYTD', GROUPING(SalesQuota) AS 'Grouping'
FROM Sales.SalesPerson
GROUP BY SalesQuota WITH ROLLUP;
GO

The result set shows two null values under SalesQuota. The first NULL represents the group of null values from this column in the table. The second NULL is in the summary row added by the ROLLUP operation. The summary row shows the TotalSalesYTD amounts for all SalesQuota groups and is indicated by 1 in the Grouping column.

Here is the result set.

SalesQuota     TotalSalesYTD       Grouping

------------   -----------------   --------

NULL           1533087.5999          0

250000.00      33461260.59           0

300000.00      9299677.9445          0

NULL           44294026.1344         1

(4 row(s) affected)

Reference