SQL SERVER – Puzzle – Incorrect Results with Decimal

It has been a while we have seen a puzzle on this blog and I keep on receiving emails and comments that you all would love to see one more puzzle. Let us see a new puzzle “Incorrect Results with Decimal”.

So the question is very simple and I expect everyone of you to get the correct answer without running the code actually in SSMS. However, due to any reason, you can’t figure out the answer, please do not hesitate to see the hints and run the entire query in SSMS.

First thing first lets us set up a table. The table contains three columns – ID, Price and Discount. We need to find out the total discount per item and final price of the product after discount.

-- Create table
CREATE TABLE #TestTable (ID INT, Price INT, Discount INT)
-- Populate table
INSERT INTO #TestTable (ID, Price, Discount)
SELECT 1, 1, 5
UNION ALL
SELECT 2, 2, 5
UNION ALL
SELECT 3, 3, 5
UNION ALL
SELECT 4, 4, 5
GO
-- Data in table
SELECT *
FROM #TestTable
GO

When we run above script we will get following answer.

Now our puzzle is to find out discount value and total final price of the product.

Here is the script which is written to find TotalDiscount and FinalPrice. However, it is giving us all the answers as 0 (zero). The script is INCORRECT.

-- SELECT statement (Incorrect result)
SELECT ID, CAST((Price*Discount)/100 AS DECIMAL(10,2)) TotalDiscount,
		Price*CAST((Price*Discount)/100 AS DECIMAL(10,2)) FinalPrice
FROM #TestTable
GO

Here is the incorrect result.

Puzzle Statement

Please fix the above script in such a way that it gives correct TotalDiscount and Final Price Value.

We are expecting the answer as in the following image.

Puzzle Hint

If you can’t figure out the correct answer, here is another image which can potentially guide you with the correct answer.

Let us see if you can give correct answer to this puzzle or not. Please share with your friends and test their knowledge about SQL as well.

NOTE: Please leave a correct answer in the comment section. I will publish all the comments together on coming Monday, till then all the answers will be hidden.

Reference: Pinal Dave (https://blog.sqlauthority.com)