sql dynaminc and aggregate functions

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sql dynaminc and aggregate functions

Lou

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Points: 2929
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March 27, 2014 at 1:29 pm

#148377

Hi,
Just looking if somebody has experienced, i have written a tql code query something like, and run ok:
Select Grade, (Count(Grade)* 100 / (Select Count(*) From MyTable)) as Score From MyTable Group By Grade
Is possible that If I embed this code in an expression like:
Set @extsql = ' Select Grade, (Count(Grade)* 100 / (Select Count(*) '
Set @extsql = @extsql+ ' From MyTable)) as Score From MyTable '
Set @extsql = @extsql+ ' Group set By Grade'
Execute (@extsql)
Our final result, were very distinct that when I run this query normally, Are the any constraint when you calculate anything using dynamic sql ?,
Any Idea would be appreciate

Viewing 5 posts - 1 through 4 (of 4 total)

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Luis Cazares SSC Guru Points: 183698 More actions · Answer 1

When you execute the code, SQL Server doesn't care if the code is dynamic or static. As long as the instruction in the dynamic code becomes exactly the same code as your static code.

You should always review your code by printing it when you're testing it.

It might be part of the obfuscation, but your codes aren't exactly the same. That could be happening in your actual query.

Luis C.
General Disclaimer:
Are you seriously taking the advice and code from someone from the internet without testing it? Do you at least understand it? Or can it easily kill your server?

How to post data/code on a forum to get the best help: Option 1 / Option 2

Sean Lange SSC Guru Points: 286573 More actions · Answer 2

To me the bigger question is why are you using dynamic sql at all? From what you posted there is absolutely no need for it whatsoever.

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Lowell SSC Guru Points: 323504 More actions · Answer 3

another issue is that query is going to use integer division and return incorrect totals

something in the query needs to be multiplied by 1.0 so that the datatype is expanded beyond integers.

1/3 = 0

1/(3 * 1.0) = 0.33

Select Grade, (Count(Grade)* 100 / (Select Count(*) From MyTable)) as Score

Select Grade, (Count(Grade)* (100 * 1.0) / (Select Count(*) From MyTable)) as Score

Lowell

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Lou SSCrazy Points: 2929 More actions · Answer 4

Thanks to all,

Your labor,ideas and toughts inspire ..