## ROUND() function doesn't round properly

 Author Message ESB SSC-Enthusiastic Group: General Forum Members Points: 146 Visits: 17 Hello. I use SQL Server 2005 and I'm calculating the age of patients in the following manner:`DATEDIFF(DAY, birthdate, operationdate)/365.25`The output always seems to be a decimal with 6 decimal digits. The rounding problem arises with border cases like for instance an age of 60.444445. If you round this properly it should result in 60.45 and that should result in 60.5. However, when I use ROUND(60.444445, 1) it results in 60.4!The problem is that SQL Server seems to ignore the digits after the rounding border. ROUND(60.449999, 1) for instance also results in 60.4. It seems to truncate it 1 position behind the rounding index and starts rounding after that. I found out that using the ROUND() function repeatedly in the following manner solves the issue but it is a bit ridiculous:`PRINT ROUND(ROUND(ROUND(ROUND(ROUND(60.444445, 5), 4), 3), 2), 1)`Is there any other way to solve this and am I missing something?Thanks in advance! Dave Ballantyne SSCoach Group: General Forum Members Points: 16908 Visits: 8370 Heres how to calculate an age`select CASEWHEN dateadd(year, datediff (year, d1, d2), d1) > d2THEN datediff (year, d1, d2) - 1ELSE datediff (year, d1, d2)END as Age`I'll take a look at the rounding issue though... Clear Sky SQLMy Blog Dave Ballantyne SSCoach Group: General Forum Members Points: 16908 Visits: 8370 I think you are wrong in your assessment of round though,round(60.444445,1) = 60.4 This `PRINT ROUND(ROUND(ROUND(ROUND(ROUND(60.444445, 5), 4), 3), 2), 1)`works because you are rounding a rounded , rounded, rounded , rounded number (ie the 5 has for want of a better word been cascaded up) Clear Sky SQLMy Blog ESB SSC-Enthusiastic Group: General Forum Members Points: 146 Visits: 17 For some reason that way of rounding was in my head. But I spoke with others about and I think SQL Server does round it correctly yes. Jeff Moden SSC Guru Group: General Forum Members Points: 504877 Visits: 44238 Dave Ballantyne (10/2/2009)Heres how to calculate an age`select CASEWHEN dateadd(year, datediff (year, d1, d2), d1) > d2THEN datediff (year, d1, d2) - 1ELSE datediff (year, d1, d2)END as Age`I'll take a look at the rounding issue though...That's one of the simplest I've seen. Correctly handles the Feb 29 problem that most other's don't handle, too! --Jeff ModenRBAR is pronounced ree-bar and is a Modenism for Row-By-Agonizing-Row.First step towards the paradigm shift of writing Set Based code: Stop thinking about what you want to do to a row... think, instead, of what you want to do to a column.If you think its expensive to hire a professional to do the job, wait until you hire an amateur. -- Red Adair Helpful Links:How to post code problemsHow to post performance problemsForum FAQs Dave Ballantyne SSCoach Group: General Forum Members Points: 16908 Visits: 8370 Cant take the credit for it ...http://windowsitpro.com/article/articleid/14267/how-can-i-calculate-someones-age-in-sql-server.html Clear Sky SQLMy Blog Jeff Moden SSC Guru Group: General Forum Members Points: 504877 Visits: 44238 Shoot... the link is broken. Thanks anyway, Dave. --Jeff ModenRBAR is pronounced ree-bar and is a Modenism for Row-By-Agonizing-Row.First step towards the paradigm shift of writing Set Based code: Stop thinking about what you want to do to a row... think, instead, of what you want to do to a column.If you think its expensive to hire a professional to do the job, wait until you hire an amateur. -- Red Adair Helpful Links:How to post code problemsHow to post performance problemsForum FAQs Dave Ballantyne SSCoach Group: General Forum Members Points: 16908 Visits: 8370 Seems fine now, just a temporary thing i guess.TBH , its hardly worth the click though :-) simple Q and A Clear Sky SQLMy Blog Jeff Moden SSC Guru Group: General Forum Members Points: 504877 Visits: 44238 Hmmmm.... something must be wrong on my end. It keeps giving me a 404 error.Q & A's are sometimes pretty rich in information like the little date jewel you found. --Jeff ModenRBAR is pronounced ree-bar and is a Modenism for Row-By-Agonizing-Row.First step towards the paradigm shift of writing Set Based code: Stop thinking about what you want to do to a row... think, instead, of what you want to do to a column.If you think its expensive to hire a professional to do the job, wait until you hire an amateur. -- Red Adair Helpful Links:How to post code problemsHow to post performance problemsForum FAQs hrothenb SSC Veteran Group: General Forum Members Points: 255 Visits: 64 DECLARE @Test TABLE ( EmpName VARCHAR(40) , BirthDate DATE );INSERT INTO @Test ( EmpName , BirthDate )VALUES ( '30 Yrs old yesterday' , DATEADD(day , -1 , DATEADD(year , -30 , GETDATE())) ) , ( '30 Yrs old today' , DATEADD(year , -30 , GETDATE()) ) , ( '30 Yrs old tomorrow' , DATEADD(day , 1 , DATEADD(year , -30 , GETDATE())) );SELECT EmpName , BirthDate , CASE WHEN DATEADD(YY , DATEDIFF(yy , BirthDate , GETDATE()) , BirthDate) < GETDATE() THEN DATEDIFF(yy , BirthDate , GETDATE()) ELSE DATEDIFF(yy , BirthDate , GETDATE()) - 1 END AS AgeFROM @Test;