Hello.
Richard Broersma Jr wrote:
> --- On Sun, 12/2/07, Hiroshi Inoue <inoue@tpf.co.jp> wrote:
>
>
>> Do you think it is an appropriate handling ?
>>
>
> This is a good question. I am not sure what an appropriate handling would be. My first test of '-infinity' (which
resultedin a raised error) was with an ado recordset. Since you are questioning what is appropriate I thought that I
shouldtry a few different client front ends to see how they treated (+/-)infinity:
>
> Client | -infinity | + infinity
> ADO | <error> |9999-12-31 23:59:59|
> Access/LT|1899-11-30 00:00:00|9999-12-31 23:59:59|
> OOB(ODBC)|0001-01-03 00:00:00|9999-12-31 23:59:59|
>
> ADO = ado recordset created in VB
> Access/LT = a linked tabled in MS-Access (probably DAO/ODBC?)
> OOB(ODBC) = Open Office.org Base ODBC connection to the Database.
>
> Having done further tests, it seems that the error must be a bug with ADO since other clients have not a problem with
making-infinity equal to the smallest time stamp that their respective data type can display. In my case, I do not
reallycare about what time stamp values are displayed by the clients for (+/-) infinity since I use these values as an
impliedNULL value for time stamps. Unfortunately, ADO is broken and can't display any value for -infinity.
>
>
>> How do you think the driver should treat -infinity ?
>>
>
> It seems that it already handles it correctly. I was mistaken in thinking that the translation of (+/-) infinity was
handledby ODBC. :o)
>
It should be handled by ODBC because of possible type conversions on the
ODBC driver layer. Take a look:
http://msdn2.microsoft.com/en-us/library/ms709280aspx. Table shows
required conversions. Also all Microsoft applications notify ODBC driver
by setting additional parameter during initialization. I think ADO
requests 'inifinity' value as SQL_C_CHAR and sure it doesn't expect it
to be 'infinity'.
> Regards,
> Richard Broersma Jr.
>
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