0

Consider these values which are of type MONEY (sample values and these can change)

select 4796.529 + 1585.0414 + 350.9863 + 223.3549 + 127.6314+479.6529 + 158.5041

for some reason I need to round each value to a scale of 3 like this

select round(4796.529,3)+ round(1585.0414,3)+ round(350.9863,3)+ round(223.3549,3)+ round(127.6314,3)+ round(479.6529,3)+ round(158.5041,3)

but when I take the sum they shows a very minor variation. first line of code returns 7721.7000. and the second one 7721.6990. But this variation in not acceptable. What is the best way to solve this ?

Vishnu Babu
  • 1,183
  • 1
  • 13
  • 37
  • 1
    ["The money and smallmoney data types are accurate to a ten-thousandth of the monetary units that they represent. For Informatica, the money and smallmoney data types are accurate to a one-hundredth of the monetary units that they represent."](https://learn.microsoft.com/en-us/sql/t-sql/data-types/money-and-smallmoney-transact-sql?view=sql-server-2017) – Zohar Peled Mar 26 '19 at 07:25
  • mathematics instead of technical, i believe. so just follow the way business requires. – Rex Mar 26 '19 at 07:28

2 Answers2

4

As Whencesoever said, your problem is mathmatical one, not a programming error.

  • 12.5 + 11.6 = 24.1
  • ROUND(12.5) + ROUND(11.6) = 25
  • ROUND(12.5 + 11.6) = 24

I'd talk with the business and figure out where they want the rounding applied.

Also, as a side note, MONEY is a terrible datatype. If you can, you may want to consider switching to a DECIMAL. See Should you choose the MONEY or DECIMAL(x,y) datatypes in SQL Server?

Moose
  • 203
  • 2
  • 10
  • if they're simply looking for a rounded total, then perhaps summing them up and rounding the result is what they're actually looking for instead of rounding each of the numbers individually? – user2366842 Mar 27 '19 at 02:27
3

When you round numbers before you sum them you will get a different result than if you round numbers after you have summed them. Simple as that. There is no way to solve this.

Dale K
  • 25,246
  • 15
  • 42
  • 71
Whencesoever
  • 2,218
  • 15
  • 26