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SQL Puzzle | Getting group by sum with Total Sum in a Single Query

This puzzle is really cool. You have to get group by sum with Total Sum in a Single query.

Please check out the sample input and the expected output below-

Sample Input
Sample Input

ID Val
1 10
1 NULL
2 NULL
2 100
2 200
3 200
3 100
4 156
4 255
4 244
4 NULL
4 NULL
4 345

Expected Output

ID COUNT
1 10
2 300
3 300
4 1000
SUM 1610

Rules/Restrictions

  • The solution should be should use “SELECT” statement or a CTE.
  • Add your solution(s) in the comments section or send you solution(s) to pawankkmr@gmail.com

Script | use below script to create table & insert some sample data


--

CREATE TABLE GroupBySumWithTotalSum
(
       ID INT
       ,VAL INT
)
GO


INSERT INTO GroupBySumWithTotalSum VALUES
(1,    10),
(1,    NULL),
(2,    NULL),
(2,    100),
(2,    200),
(3,    200),
(3,    100),
(4,    156),
(4,    255),
(4,    244),
(4,    NULL),
(4,    NULL),
(4,    345)
GO

CREATE CLUSTERED INDEX Ix_ID ON GroupBySumWithTotalSum(ID)
GO


--

Solution 1


--

SELECT ISNULL(CAST(Id AS VARCHAR(3)),'Sum') Id, SUM(Val) Val FROM GroupBySumWithTotalSum
GROUP BY Id WITH ROLLUP


--

Solution 2


--

SELECT ISNULL(CAST(Id AS VARCHAR(3)),'Sum') Id, SUM(Val) Val FROM GroupBySumWithTotalSum
GROUP BY Id WITH CUBE

--

Solution 3


--

SELECT CAST(Id AS VARCHAR(3)) Id, SUM(Val) Val FROM GroupBySumWithTotalSum
GROUP BY Id
UNION ALL
SELECT 'Sum', SUM(Val) FROM GroupBySumWithTotalSum

--

Execution Plan / Performance Comparison

Clearly the first & second method are the best one as in the third query we are hitting the table twice and there is a conversion warning also @ the beginning of the third query.

Add a comment if you have any other solution in mind. I would love to learn it. We all need to learn.

Enjoy !!! Keep Learning

Pawan Khowal 

Http://MSBISkills.com

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