YuePing Lu wrote:
> Hello,
>
> Has any of you ever used Python odbc to retrieve data from a relational DB?
>
> I encountered a problem where it can't handle datetime _earlier than
> _*1969*, and _later than _*2040*. It just returned some garbage strings
> when I call str(my_date_object).
>
> When I call strptime to convert the value I got ValueError exception:
>
> # Table records
> for record in self._records:
> columns = []
> for i in range(len(self._description)):
> if self._description[i][1]=='DATE':
> strDate=str(record[i])
> try:
> #convert the date format to be mm/dd/yyyy:
> oDate=time.strptime(strDate) #convert to struct_time object
> strfDate=time.strftime("%m/%d/%Y", oDate)
>
> columns.append(strfDate)
> except ValueError, msg:
> raise "Date converstion error", msg
>
> ...
> Any other solutions that you've heard?
>
> Thanks very much in advance,
>
Reading the documentation for the time module, you will see:
The epoch is the point where the time starts. On January 1st of that
year, at 0 hours, the ``time since the epoch'' is zero. For Unix, the
epoch is 1970. To find out what the epoch is, look at gmtime(0).
The functions in this module do not handle dates and times before the
epoch or far in the future. The cut-off point in the future is
determined by the C library; for Unix, it is typically in 2038.
So this may not be a problem with the odbc module, which isn't the most
up-to-date piece of software on the block but is mostly reliable for
simple purposes.
I'd try something from the datetime module. When I retrieve a date
column from a postgreSQL database using ODBC is see:
>>> curs.execute("SELECT orginvdt FROM organization WHERE orginvdt IS
NOT NULL")
0
>>> row = curs.fetchone()
>>> row
(<DbiDate object at 0x0099D0A0>,)
>>> dbidate = row[0]
>>> dir(dbidate)
[]
So it isn't easy to know just by looking what you can do with a
dbitdate. But if you can hack around with the time module you can
probably hack around with datetime too, and that's a more capable
module. However it's possible that the epoch-to-2038 restriction is
actually imposed byt he odbc drivers, in which case you will need to
look for another Python driver module for your database.
It would have been helpful if you hadn't trapped the exception so that
we could have seen the exact traceback - this would have given man more
clues as to what was going on.
regards
Steve
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