[egenix-users] way to prevent floats from truncating to ints?

[M.-A. Lemburg]

On 2008-04-21 19:06, Nathan Gossett wrote:
> Although we were never able to get the latest ODBC drivers to install 
> correctly, we did manage to work around the issue by changing the 
> offending column from a FLOAT to a NUMBER(10,2) type, which is correctly 
> passed along without truncation even with the older driver.  This might 
> not be a total solution to the issue, but it will work for our purposes 
> and I thought I'd pass it along for future reference.

Thank you for providing this tip.

Perhaps it's also possible to convince the ODBC driver to send
correct precision information by using CAST() in the queries.

> M.-A. Lemburg wrote:
>> On 2008-04-09 22:26, Nathan Gossett wrote:
>>> I'm using mxODBC to work with an Oracle 9 database, and when I try to 
>>> fetch FLOAT data, they are being returned as ints.  Basically, I'm 
>>> having the same issue as problem two in this posting:
>>>
>>> http://www.egenix.com/mailman-archives/egenix-users/2003-June/113452.html 
>>>
>>>
>>> Setting the "leave scale 0 floats untouched" option is not really a 
>>> solution, because then all of the NUMBER(10,0) data is returned as 
>>> floats (which causes problems since they are supposed to be 
>>> integers). I realize that mxODBC is acting exactly as documented, but 
>>> I need floats to be returned as floating point numbers, while 
>>> integers are returned as integers.  Is there some way around this?
>>
>> What you are seeing is caused by a bug in the Oracle ODBC driver
>> you are using: it returns a scale 0 value for regular floating
>> values instead of the true value. As a result the mxODBC Zope DA
>> then assumes that the scale of the float value is indeed 0 and
>> thus an integer and truncates the values depending on the setting
>> of the connection option.
>>
>> There are ways to work around this problem by fetching all numbers
>> as floats and then applying the conversion from floats to integers
>> where necessary "by hand", but this is not ideal.
>>
>> Please first try with the latest Oracle ODBC driver from the
>> Oracle Full Client (not the Oracle Instance Client), apply
>> all available patches and let us know whether the problem still
>> persists with that driver version.
>>
>> If that doesn't help either, we'll have to add a work-around to the
>> underlying mxODBC Python interface and include that in the next version
>> of the mxODBC Zope DA.
>>
>> Thanks,
> 
> 
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