Rails activerecord: query for record by a datetime field?

I'm trying to query for records in the TimeSlot table by the field start_date which has type datetime开发者_开发百科. Here's what I've tried so far that's failed:

TimeSlot.where(:start_date => DateTime.new(2010, 9, 1))

TimeSlot.where(:start_date => DateTime.new(2010, 9, 1).to_s)

TimeSlot.where(:start_date => "2010-09-08")

TimeSlot.where(:start_date => "2010-09-08 00:00:00")

I'd appreciate any help.

Your queries look good to me.

Are you sure that you have a matching row in the db?

To debug, look in your logs/development.log file.

Added:

Problem could be timezones. Your query is using your server's timezone. Your data could be stored in a different timezone.

I'm betting it is a timezone thing as well. Everything in the DB is automatically converted to UTC by rails. Queries 1 and 4 should work if there isn't an offset.

Answer from rubyonrails.org

Client.where("created_at >= :start_date AND created_at <= :end_date", {:start_date => params[:start_date], :end_date => params[:end_date]})

or

Client.where("created_at IN (?)", (params[:start_date].to_date)..(params[:end_date].to_date))

Here is what I have for query all the TimeSlot start at "2010-09-08", if your start_date is a date field.

TimeSlot.where("start_date >= ? AND start_date <= ?", "2010-09-08", "2010-09-08")

If you start_date is a datetime field.

TimeSlot.where("start_date >= ? AND start_date <= ?", "2010-09-08", "2010-09-09")

Because the datetime start at 00:00:00