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sqlite: calculating with dates - compare current date minus 6 months with stored record
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DateTime::Format::SQLite(3pm) User Contributed Perl Documentation DateTime::Format::SQLite(3pm) NAME
DateTime::Format::SQLite - Parse and format SQLite dates and times SYNOPSIS
use DateTime::Format::SQLite; my $dt = DateTime::Format::SQLite->parse_datetime( '2003-01-16 23:12:01' ); # 2003-01-16 23:12:01 DateTime::Format::SQLite->format_datetime($dt); DESCRIPTION
This module understands the formats used by SQLite for its "date", "datetime" and "time" functions. It can be used to parse these formats in order to create DateTime objects, and it can take a DateTime object and produce a timestring accepted by SQLite. NOTE: SQLite does not have real date/time types but stores everything as strings. This module deals with the date/time strings as understood/returned by SQLite's "date", "time", "datetime", "julianday" and "strftime" SQL functions. You will usually want to store your dates in one of these formats. METHODS
This class offers the methods listed below. All of the parsing methods set the returned DateTime object's time zone to the UTC zone because SQLite does always uses UTC for date calculations. This means your dates may seem to be one day off if you convert them to local time. o parse_datetime($string) Given a $string representing a date, this method will return a new "DateTime" object. The $string may be in any of the formats understood by SQLite's "date", "time", "datetime", "julianday" and "strftime" SQL functions or it may be in the format returned by these functions (except "strftime", of course). The time zone for this object will always be in UTC because SQLite assumes UTC for all date calculations. If $string contains no date, the parser assumes 2000-01-01 (just like SQLite). If given an improperly formatted string, this method may die. o parse_date($string) o parse_time($string) o parse_julianday($string) These are aliases for "parse_datetime", for symmetry with "format_*" functions. o format_date($datetime) Given a "DateTime" object, this methods returnes a string in the format YYYY-MM-DD, i.e. in the same format SQLite's "date" function uses. o format_time($datetime) Given a "DateTime" object, this methods returnes a string in the format HH:MM:SS, i.e. in the same format SQLite's "time" function uses. o format_datetime($datetime) Given a "DateTime" object, this methods returnes a string in the format YYYY-MM-DD HH:MM:SS, i.e. in the same format SQLite's "datetime" function uses. o format_julianday($datetime) Given a "DateTime" object, this methods returnes a string in the format DDDDDDDDDD, i.e. in the same format SQLite's "julianday" function uses. AUTHOR
Claus Faerber <CFAERBER@cpan.org> based on "DateTime::Format::MySQL" by David Rolsky. Copyright X 2008 Claus Faerber. Copyright X 2003 David Rolsky. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself. The full text of the license can be found in the LICENSE file included with this module. SEE ALSO
http://datetime.perl.org/ http://www.sqlite.org/lang_datefunc.html perl v5.10.1 2009-12-10 DateTime::Format::SQLite(3pm)
