DateTime::Format::Oracle - Parse and format Oracle dates and timestamps

Acknowledgements

       I might have put this module off for another couple years  without  the  lure  of  Jifty,  Catalyst,  and
       DBIx::Class pulling at me.

       Thanks to Dan Horne for his RFC draft of this module.

Author

       Nathan Gray, <kolibrie@cpan.org>

Copyright & License

       Copyright (C) 2006, 2008, 2011 Nathan Gray.

       This  library  is  free  software;  you can redistribute it and/or modify it under the same terms as Perl
       itself, either Perl version 5.8.4 or, at your option, any later version of Perl 5 you may have available.

Description

       This module may be used to convert Oracle date and timestamp values into "DateTime" objects.  It also can
       take a "DateTime" object and produce a date string matching the "NLS_DATE_FORMAT".

       Oracle has flexible date formatting via its "NLS_DATE_FORMAT" session variable.  Date values will be
       returned from Oracle according to the current value of that variable.  Date values going into Oracle must
       also match the current setting of "NLS_DATE_FORMAT".

       Timestamp values will match either the "NLS_TIMESTAMP_FORMAT" or "NLS_TIMESTAMP_TZ_FORMAT" session
       variables.

       This module keeps track of these Oracle session variable values by examining environment variables of the
       same name.  Each time one of Oracle's formatting session variables is updated, the %ENV hash must also be
       updated.

Limitations

       Oracle is more flexible with the case of names, such as the month, whereas "DateTime"  generally  returns
       names in "ucfirst" format.

         MONTH -> FEBRUARY
         Month -> February
         month -> february

       All translate to:

         %B    -> February

   TIMEZONES
       Oracle  returns  all  dates  and  timestamps in a time zone similar to the "DateTime" floating time zone,
       except for 'timestamp with time zone' columns.

   INTERVALELEMENTS
       I have not implemented "parse_duration", "format_duration", "parse_interval", nor "format_interval",  and
       have no plans to do so.

       If  you  need  these  features, unit tests, method implementations, and pointers to documentation are all
       welcome.

Methods

This class offers the following methods.

• nls_date_format

This method is used to determine the current value of Oracle's "NLS_DATE_FORMAT". It currently just
reads the value from

$ENV{'NLS_DATE_FORMAT'}

or if that is not set, from the package variable $nls_date_format, which has a default value of
"YYYY-MM-DD HH24:MI:SS". This is a good default to have, but is not Oracle's default. Dates will
fail to parse if Oracle's NLS_DATE_FORMAT and the value from this method are not the same.

If you want to use the default from this module, you can do something like this after you connect to
Oracle:

$dbh->do(
"alter session set nls_date_format = '" .
DateTime::Format::Oracle->nls_date_format .
"'"
);

• nls_timestamp_format

This method is used to determine the current value of Oracle's "NLS_TIMESTAMP_FORMAT". It currently
just reads the value from

$ENV{'NLS_TIMESTAMP_FORMAT'}

or if that is not set, from the package variable $nls_timestamp_format, which has a default value of
"YYYY-MM-DD HH24:MI:SS". This is a good default to have, but is not Oracle's default. Dates will
fail to parse if Oracle's NLS_TIMESTAMP_FORMAT and the value from this method are not the same.

If you want to use the default from this module, you can do something like this after you connect to
Oracle:

$dbh->do(
"alter session set nls_timestamp_format = '" .
DateTime::Format::Oracle->nls_timestamp_format .
"'"
);

• nls_timestamp_tz_format

This method is used to determine the current value of Oracle's "NLS_TIMESTAMP_TZ_FORMAT". It
currently just reads the value from

$ENV{'NLS_TIMESTAMP_TZ_FORMAT'}

or if that is not set, from the package variable $nls_timestamp_tz_format, which has a default value
of "YYYY-MM-DD HH24:MI:SS TZHTZM". This is a good default to have, but is not Oracle's default.
Dates will fail to parse if Oracle's NLS_TIMESTAMP_TZ_FORMAT and the value from this method are not
the same.

If you want to use the default from this module, you can do something like this after you connect to
Oracle:

$dbh->do(
"alter session set nls_timestamp_tz_format = '" .
DateTime::Format::Oracle->nls_timestamp_tz_format .
"'"
);

• parse_datetime

Given a string containing a date and/or time representation matching "NLS_DATE_FORMAT", this method
will return a new "DateTime" object.

If given an improperly formatted string, this method may die.

• parse_date

Alias to "parse_datetime". Oracle's date datatype also holds time information.

• parse_timestamp

Given a string containing a date and/or time representation matching "NLS_TIMESTAMP_FORMAT", this
method will return a new "DateTime" object.

If given an improperly formatted string, this method may die.

• parse_timestamptz =item * parse_timestamp_with_time_zone

Given a string containing a date and/or time representation matching "NLS_TIMESTAMP_TZ_FORMAT", this
method will return a new "DateTime" object.

If given an improperly formatted string, this method may die.

• current_date_parser

The current "DateTime::Format::Builder" generated parsing method used by "parse_datetime" and
"parse_date".

• current_timestamp_parser

The current "DateTime::Format::Builder" generated parsing method used by "parse_timestamp".

• current_timestamptz_parser

The current "DateTime::Format::Builder" generated parsing method used by "parse_timestamptz".

• format_datetime

Given a "DateTime" object, this method returns a string matching the current value of
"NLS_DATE_FORMAT".

It is important to keep the value of $ENV{'NLS_DATE_FORMAT'} the same as the value of the Oracle
session variable "NLS_DATE_FORMAT".

To determine the current value of Oracle's "NLS_DATE_FORMAT":

select NLS_DATE_FORMAT from NLS_SESSION_PARAMETERS

To reset Oracle's "NLS_DATE_FORMAT":

alter session set NLS_DATE_FORMAT='YYYY-MM-DD HH24:MI:SS'

It is generally a good idea to set "NLS_DATE_FORMAT" to an unambiguos value, with four-digit year,
and hour, minute, and second.

• format_date

Alias to "format_datetime".

• format_timestamp

Given a "DateTime" object, this method returns a string matching the current value of
"NLS_TIMESTAMP_FORMAT".

It is important to keep the value of $ENV{'NLS_TIMESTAMP_FORMAT'} the same as the value of the Oracle
session variable "NLS_TIMESTAMP_FORMAT".

To determine the current value of Oracle's "NLS_TIMESTAMP_FORMAT":

select NLS_TIMESTAMP_FORMAT from NLS_SESSION_PARAMETERS

To reset Oracle's "NLS_TIMESTAMP_FORMAT":

alter session set NLS_TIMESTAMP_FORMAT='YYYY-MM-DD HH24:MI:SS'

It is generally a good idea to set "NLS_TIMESTAMP_FORMAT" to an unambiguos value, with four-digit
year, and hour, minute, and second.

• format_timestamptz =item * format_timestamp_with_time_zone

Given a "DateTime" object, this method returns a string matching the current value of
"NLS_TIMESTAMP_TZ_FORMAT".

It is important to keep the value of $ENV{'NLS_TIMESTAMP_TZ_FORMAT'} the same as the value of the
Oracle session variable "NLS_TIMESTAMP_TZ_FORMAT".

To determine the current value of Oracle's "NLS_TIMESTAMP_TZ_FORMAT":

select NLS_TIMESTAMP_TZ_FORMAT from NLS_SESSION_PARAMETERS

To reset Oracle's "NLS_TIMESTAMP_TZ_FORMAT":

alter session set NLS_TIMESTAMP_TZ_FORMAT='YYYY-MM-DD HH24:MI:SS TZHTZM'

It is generally a good idea to set "NLS_TIMESTAMP_TZ_FORMAT" to an unambiguos value, with four-digit
year, and hour, minute, and second.

• current_date_format

The current generated method used by "format_datetime", "format_date", and "current_date_parser" to
keep track of the "strptime" translation of "NLS_DATE_FORMAT".

• current_timestamp_format

The current generated method used by "format_timestamp", "format_timestamp_with_time_zone", and
"current_timestamp_parser" to keep track of the "strptime" translation of "NLS_TIMESTAMP_FORMAT".

• current_timestamptz_format

The current generated method used by "format_timestamptz", "format_timestamp_with_time_zone", and
"current_timestamp_parser" to keep track of the "strptime" translation of "NLS_TIMESTAMP_FORMAT".

• oracle_to_posix

Given an "NLS_DATE_FORMAT", "NLS_TIMESTAMP_FORMAT", or "NLS_TIMESTAMP_TZ_FORMAT" value, this method
returns a "DateTime"-compatible "strptime" format value.

Translation is currently handled by "Convert::NLS_DATE_FORMAT".

Name

       DateTime::Format::Oracle - Parse and format Oracle dates and timestamps

Support

       Support for this module is provided via the datetime@perl.org email list.  See http://lists.perl.org/ for
       more details.

Synopsis

         use DateTime::Format::Oracle;

         $ENV{'NLS_DATE_FORMAT'} = 'YYYY-MM-DD HH24:MI:SS';
         my $dt = DateTime::Format::Oracle->parse_datetime('2003-01-16 23:12:01');
         my $string = DateTime::Format::Oracle->format_datetime($dt);

Todo

       Possibly read an environment variable to determine a time zone to use instead of 'floating'.

       Test and document creating an instance via "new".

return

DateTime::Format::Oracle - Parse and format Oracle dates and timestamps

Contents

Acknowledgements

Author

Copyright & License

Description

Limitations

Methods

Name

See Also

Support

Synopsis

Todo

See Also