From: Ammar Ali <ammarabuali@...>
Date: 2010-01-23T16:04:32+09:00
Subject: Re: search datetime column for all records that start at 11:00

Morgan Morgan wrote:
> i have to count how many records are in a database that have a start
> time of 11:00 for an entire year.   the problem is, i can't seem to find
> out how to coax rails into ignoring the date to just search for a time.
>   

If I understand your question correctly, then this is handled 
differently by different databases.

For example, mysql uses DATE_FORMAT/TIME_FORMAT, sqlite uses STRFTIME, 
and PostgreSQL uses the powerful extract/to_char. See the manual for 
your specific database on how to extract and format parts of the a 
datetime column for use it in comparisons/queries.

 From rails, you could specify this custom SQL as a :condition to find, 
or use execute(sql).

The last time I needed similar functionality, I didn't find any built-in 
methods to accomplish this in rails. Would like to know if one exists 
and I somehow missed it.

hth,
ammar