[DB-SIG] should precision and sign of decimal(0) be significant?

[M.-A. Lemburg]

On 08.05.2013 11:48, Vernon D. Cole wrote:
> I am working on code (django-mssql) where I found the following test:
> 
> ##            expected = (
> ##                Decimal('0.00'),
> ##                Decimal('0.0'),
> ##                Decimal('-0.00'))
> ##
> ##            cur = con.cursor()
> 
> ##            cur.paramstyle = 'format'  # a nonstandard extension -- VDC
> 
> ##            cur.execute("SELECT %s as A, %s as B, %s as C", expected)
> ##
> ##            result = cur.fetchall()
> ##            self.assertEqual(result[0], expected)
> 
> I added the paramstyle alteration, to match the original test's assumption
> -- that is not what I am asking about.  My question is: is this test
> reasonable on it's face?
> 
> I personally think that all values of zero are equal, and the user should
> have no expectation that neqative zero, or an accurately precise zero,
> should be returned. My present code returns three copies of Decimal(0).
> 
> But someone must disagree, or this test would not have been written.
> 
> What is the feeling of the group?

It's possible that the DB module passes decimals as
strings to the database and the database could treat them
differently in the resp. string form (e.g. raise an error
in case the precision doesn't match).

The test will pass either way, since all values compare
equal.

-- 
Marc-Andre Lemburg
eGenix.com

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