From: akr@...
Date: 2020-12-26T14:49:45+00:00
Subject: [ruby-core:101718] [Ruby master Feature#16005] A variation of Time.iso8601 that can parse yyyy-MM-dd HH:mm:ss

Issue #16005 has been updated by akr (Akira Tanaka).


naruse (Yui NARUSE) wrote in #note-11:

> * Time#sql_timestamp for serializer

Time#sql_timestamp needs to convert rational subsec to finite digits (or raise an error).
truncate to nanoseconds?


----------------------------------------
Feature #16005: A variation of Time.iso8601 that can parse yyyy-MM-dd HH:mm:ss
https://bugs.ruby-lang.org/issues/16005#change-89541

* Author: matsuda (Akira Matsuda)
* Status: Open
* Priority: Normal
* Target version: 3.1
----------------------------------------
Let me propose a String to Time conversion method that can parse "yyyy-MM-dd HH:mm:ss" format, which is very much similar to `Time.iso8601`, but delimits the date part and the time part with a space character.

This format is defined as the "timestamp string" literal in SQL 92 standard: http://www.contrib.andrew.cmu.edu/~shadow/sql/sql1992.txt (see P. 90)
and so this format is very widely used as the default datetime / timestamp literal for major existing RDBMS implementations.

Oracle
https://docs.oracle.com/en/database/oracle/oracle-database/19/sqlrf/Literals.html#GUID-8F4B3F82-8821-4071-84D6-FBBA21C05AC1

SQL Server
https://docs.microsoft.com/en-us/sql/odbc/reference/develop-app/date-time-and-timestamp-literals?view=sql-server-2017

PostgreSQL
https://www.postgresql.org/docs/11/datatype-datetime.html#id-1.5.7.13.19.7.2

MySQL
https://dev.mysql.com/doc/refman/8.0/en/datetime.html

SQLite3
https://www.sqlite.org/lang_datefunc.html

In order to handle this conversion in Ruby on Rails framework, we define our own String => Time conversion method
https://github.com/rails/rails/blob/b4c715fe/activemodel/lib/active_model/type/helpers/time_value.rb#L62-L76
and Time => String conversion for now,
https://github.com/rails/rails/blob/b4c715fe/activesupport/lib/active_support/core_ext/time/conversions.rb#L7-L59
and I think it's nicer if we had them in the language level with a faster implementation.

As for the method name, maybe we can name it `Time.sql92`, `Time.sql`, `Time.parse_sql92` or whatever, or maybe we can add an option to `Time.iso8601` if it could be regarded as a variation of `Time.iso8601`? (https://en.wikipedia.org/wiki/ISO_8601#cite_note-30)



-- 
https://bugs.ruby-lang.org/

Unsubscribe: <mailto:ruby-core-request@ruby-lang.org?subject=unsubscribe>
<http://lists.ruby-lang.org/cgi-bin/mailman/options/ruby-core>