SQL Server tutorial for beginners - Grouping Sets in SQL Server

grouping sets examples in sql server sql server grouping sets order by grouping sql server 2008 grouping sets example sql server group by union all Grouping sets is a new feature introduced in SQL Server 2008. Let us understand Grouping sets with an example. Healthy diet is very important both for the body and mind. If you like Aarvi Kitchen recipes, please support by sharing, subscribing and liking our YouTube channel. Hope you can help. https://www.youtube.com/channel/UC7sEwIXM_YfAMyonQCrGfWA/?sub_confirmation=1 We want to calculate Sum of Salary by Country and Gender. We can very easily achieve this using a Group By query as shown below Select Country, Gender, Sum(Salary) as TotalSalary From Employees Group By Country, Gender Within the same result set we also want Sum of Salary just by Country. To achieve the above result we could combine 2 Group By queries using UNION ALL as shown below. Select Country, Gender, Sum(Salary) as TotalSalary From Employees Group By Country, Gender UNION ALL Select Country, NULL, Sum(Salary) as TotalSalary From Employees Group By Country Within the same result set we also want Sum of Salary just by Gender. We can achieve this by combining 3 Group By queries using UNION ALL as shown below Select Country, Gender, Sum(Salary) as TotalSalary From Employees Group By Country, Gender UNION ALL Select Country, NULL, Sum(Salary) as TotalSalary From Employees Group By Country UNION ALL Select NULL, Gender, Sum(Salary) as TotalSalary From Employees Group By Gender Finally we also want the grand total of Salary. In this case we are not grouping on any particular column. So both Country and Gender columns will be NULL in the resultset. To achieve this we will have to combine the fourth query using UNION ALL as shown below. Select Country, Gender, Sum(Salary) as TotalSalary From Employees Group By Country, Gender UNION ALL Select Country, NULL, Sum(Salary) as TotalSalary From Employees Group By Country UNION ALL Select NULL, Gender, Sum(Salary) as TotalSalary From Employees Group By Gender UNION ALL Select NULL, NULL, Sum(Salary) as TotalSalary From Employees There are 2 problems with the above approach. The query is huge as we have combined different Group By queries using UNION ALL operator. This can grow even more if we start to add more groups The Employees table has to be accessed 4 times, once for every query. If we use Grouping Sets feature introduced in SQL Server 2008, the amount of T-SQL code that you have to write will be greatly reduced. The following Grouping Sets query produce the same result as the above UNION ALL query. Select Country, Gender, Sum(Salary) TotalSalary From Employees Group BY GROUPING SETS ( (Country, Gender), -- Sum of Salary by Country and Gender (Country), -- Sum of Salary by Country (Gender) , -- Sum of Salary by Gender () -- Grand Total ) The order of the rows in the result set is not the same as in the case of UNION ALL query. To control the order use order by as shown below. Select Country, Gender, Sum(Salary) TotalSalary From Employees Group BY GROUPING SETS ( (Country, Gender), -- Sum of Salary by Country and Gender (Country), -- Sum of Salary by Country (Gender) , -- Sum of Salary by Gender () -- Grand Total ) Order By Grouping(Country), Grouping(Gender), Gender Text version of the video http://csharp-video-tutorials.blogspot.com/2015/09/grouping-sets-in-sql-server.html Slides http://csharp-video-tutorials.blogspot.com/2015/09/grouping-sets-in-sql-server_19.html All SQL Server Text Articles http://csharp-video-tutorials.blogspot.com/p/free-sql-server-video-tutorials-for.html All SQL Server Slides http://csharp-video-tutorials.blogspot.com/p/sql-server.html All Dot Net and SQL Server Tutorials in English https://www.youtube.com/user/kudvenkat/playlists?view=1&sort=dd All Dot Net and SQL Server Tutorials in Arabic https://www.youtube.com/c/KudvenkatArabic/playlists