Re: [cx-oracle-users] Fetching NaN, -Infinity and +Infinity from BINARY_FLOAT or BINARY_DOUBLE columns

[Amaury F. d'A. <ama...@gm...>]

Hello,

Boxhoorn wrote:
>
> When fetching a NaN number (nan in Python) from a BINARY_FLOAT or BINARY_DOUBLE
> column, the following exception is raised.
>
>    Traceback (most recent call last):
>      File "<stdin>", line 1, in ?
>    cx_Oracle.DatabaseError: ORA-01722: invalid number
>
> Similary, fetching Infinity (inf in Python) from a BINARY_FLOAT or BINARY_DOUBLE
> column results in
>
>    Traceback (most recent call last):
>      File "<stdin>", line 1, in ?
>    cx_Oracle.DatabaseError: OCI-22065: number to text translation for the given format causes overflow
>
> Inserting Infinity and NaN, however, works flawlessly.

cx_Oracle always uses the OciNumber type to exchange numeric values
with the database (this is the C equivalent of the NUMBER datatype).
Here the error messages comes from the oci layer trying to convert
your data into NUMBER values.

Well, this won't help you, but I remember Anthony's proposal about
following more closely the Python type when creating bind variables:
http://sourceforge.net/mailarchive/forum.php?thread_id=30737382&forum_id=34464
I don't know how far he went in this direction, but an easy addition
to his proposal is to create a BINARY_DOUBLE bind variable when the
python type is 'double'.
Then special values should pass unmodified from the database to the
python client.
Maybe wait for a future relase?

-- 
Amaury Forgeot d'Arc