[odb-users] Storing NaN in the datadbase

[Alexander A. Prokhorov]

Great, it works, thanks again.

On 18.07.2012 16:57, Alexander A. Prokhorov wrote:
> Thank you, Boris - I'll try.
>
> On 18.07.2012 14:13, Boris Kolpackov wrote:
>> Hi Alexander,
>>
>> Alexander A. Prokhorov <prokher at gmail.com> writes:
>>
>>> class Value : public DbObject {
>>>    friend class odb::access;
>>>    double _value;
>>> };
>>>
>>> Everything is fine until Value::_value becomes NaN, when calling 
>>> persist
>>> for such objects I got the following error: 'object already persistent'
>>> is it possible to store NaN's in database with odb?
>> Hm, according to this thread[1], SQLite converts NaNs to NULLs for some,
>> perhaps misguided, reason. To be consistent, I updated libodb-sqlite to
>> convert NULLs back to NaNs for consistency. So to make NaNs work you 
>> will
>> need to do two things:
>>
>> 1. Apply this patch to libodb-sqlite:
>>
>> http://scm.codesynthesis.com/?p=odb/libodb-sqlite.git;a=commit;h=3fabd5107e81d1f75a259ba1d1fa1911c166ebac 
>>
>>
>> 2. Enable NULLs for the members that store NaNs:
>>
>> class Value : public DbObject {
>>
>>    #pragma db null
>>    double _value;
>> };
>>
>> [1] http://comments.gmane.org/gmane.comp.db.sqlite.general/73139
>>
>> Boris
>