Re: [Ruby-DBI-devel-CVS] CVS: src/lib/dbi sql.rb,1.13,1.14

[Paul D. <pa...@sn...>]

At 20:49 +0200 4/27/03, Michael Neumann wrote:
>Paul DuBois wrote:
>>  At 10:37 -0700 4/27/03, Michael Neumann wrote:
>>  >Update of /cvsroot/ruby-dbi/src/lib/dbi
>>  >In directory sc8-pr-cvs1:/tmp/cvs-serv23497
>>  >
>>  >Modified Files:
>>  >	sql.rb
>>  >Log Message:
>>  >Fixed bug in DBI::SQL::BasicQuote::Coerce#as_time
>>  >Mysql time columns (like "13:32:33") could not be converted into
>>  >DBI::Time objects
>>  >(thanks to Tim Bates)
>>
>>  Speaking of coercion...
>>
>>  I've noticed that MySQL DATETIME and TIMESTAMP values get converted
>>  into formats that don't really reflect how MySQL itself displays
>>  them.  For example, a DATETIME value such as '2001-01-01 00:00:00'
>>  gets coerced to '2001-1-1 0:0:0.0'.  Leading zeros are lost, and
>>  a fraction-of-seconds part is added at the end.
>>
>>  Should this be considered a bug, or just something that MySQL
>>  users should be aware of, and wary of?
>
>The string we get from a Mysql database is parsed and converted into
>a DBI::Time object. When calling the to_s method of DBI::Time it
>is converted back into a string.
>
>Does Mysql handle '2001-1-1 0:0:0.0' correctly as a DATETIME value?

Yes, though this is because it ignores the fractional part (the .0)
at the end, which is not part of DATETIME or TIMESTAMP.


>And "0:0:0" for TIME values?

Yes.

>If not, than it's a bug, otherwise not.

On the other hand, your questions relate to putting data *into* MySQL.
Applications that expect DATETIME values to come *out* of Ruby DBI programs
the way that MySQL itself formats them may break.  (That is, if a
program assumes a string value in CCYY-MM-DD hh:mm:ss format, it cannot
break out parts of the value by looking for fixed-length-and-position
substrings.)  That's why I asked if this behavior is something MySQL
users should be wary of.

>
>When can of course modify the to_s method to output YYYY-MM-DD HH:MM:SS.F,
>that's no problem, except perhaps decreased performance (should be ok).

There would be no ".F" part for MySQL.

>
>Regards,
>
>   Michael