# About active\_record timestamps **URL:** \ **Category:** Rails\ **Created:** [July 15, 2010, 11:57am UTC](https://www.ruby-forum.com/t/about-active-record-timestamps/191616 "2010-07-15T11:57:44Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![daociyiyou](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/0ea827/32.png) [@daociyiyou](https://www.ruby-forum.com/u/daociyiyou)\ **Post date:** [July 15, 2010, 11:57am UTC](https://www.ruby-forum.com/t/about-active-record-timestamps/191616/1 "2010-07-15T11:57:44Z")
hi I want to build a filter that gets records from database based on selected date.such as #### Product.find(:all, :conditions =\> [“created\_at = ?”,selected\_date]) #### 1 If selected\_date is a Date object while created\_at is a DateTime object,is it work? 2 Do i need to set this? #### ActiveRecord::Base.default\_timezone = :utc #### My talbe has another date type field which i want it to be local timezone,so it seems i should not set ActiveRecord::Base.default\_timezone = :utc,but my filter will not works well because of the default local timezone setting for the createdz\_at attribute.How to resolve these problem? Thanks! ---
**Author:** ![daociyiyou](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/0ea827/32.png) [@daociyiyou](https://www.ruby-forum.com/u/daociyiyou)\ **Post date:** [July 15, 2010, 7:19pm UTC](https://www.ruby-forum.com/t/about-active-record-timestamps/191616/2 "2010-07-15T19:19:38Z")
On Jul 15, 2010, at 2:57 AM, Guo Y. wrote: > hi > I want to build a filter that gets records from database based on > selected date.such as > > #### > > Product.find(:all, :conditions =\> [“created\_at = ?”,selected\_date]) > > #### > > 1 If selected\_date is a Date object while created\_at is a DateTime > object,is it work? > 2 Do i need to set this? It will work just fine. However, it won’t do what you want… created\_at is going to contain date/time down to the second (or more). If you pass in a date of “2010-07-15” it’s going to append a time of “00:00:00” (most likely). So you’re not going to get records created anytime during that day. I’m guessing that’s what you want. If so you need to modify that to check for any record created on that _date_ using a range or something else. ---
**Author:** ![daociyiyou](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/0ea827/32.png) [@daociyiyou](https://www.ruby-forum.com/u/daociyiyou)\ **Post date:** [July 15, 2010, 9:11pm UTC](https://www.ruby-forum.com/t/about-active-record-timestamps/191616/3 "2010-07-15T21:11:29Z")
On Jul 15, 2010, at 1:17 PM, Philip H. wrote: > > #### > > > > ## Thanks! Try: Product.find(:all, :conditions =\> [“DATE(created\_at) = ?”, selected\_date]) -Rob Rob B. removed\_email\_address@domain.invalid [http://AgileConsultingLLC.com/](http://AgileConsultingLLC.com/) removed\_email\_address@domain.invalid [http://GaslightSoftware.com/](http://GaslightSoftware.com/) ---
**Author:** ![daociyiyou](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/0ea827/32.png) [@daociyiyou](https://www.ruby-forum.com/u/daociyiyou)\ **Post date:** [July 15, 2010, 9:57pm UTC](https://www.ruby-forum.com/t/about-active-record-timestamps/191616/4 "2010-07-15T21:57:44Z")
On Thu, Jul 15, 2010 at 10:09 PM, Rob B. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > > > ## 1 If selected\_date is a Date object while created\_at is a DateTime for any record created on that _date_ using a range or something else. Thanks! > > Try: > > Product.find(:all, :conditions =\> [“DATE(created\_at) = ?”, selected\_date]) > > -Rob But have in mind that this wont use the created\_at index (if you have one) ---
**Author:** ![daociyiyou](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/0ea827/32.png) [@daociyiyou](https://www.ruby-forum.com/u/daociyiyou)\ **Post date:** [July 15, 2010, 9:57pm UTC](https://www.ruby-forum.com/t/about-active-record-timestamps/191616/5 "2010-07-15T21:57:45Z")
On 15 July 2010 20:09, Rob B. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > > > ## 1 If selected\_date is a Date object while created\_at is a DateTime for any record created on that _date_ using a range or something else. Thanks! > > Try: > > Product.find(:all, :conditions =\> [“DATE(created\_at) = ?”, selected\_date]) Will that have to do a calculation on every record to determine DATE? If so would it be more efficient to specify a range for created\_at instead (something like \>= selected\_date and \< selected\_date + 1.day)? Particularly if there were an index on the column. Colin ---
**Author:** ![daociyiyou](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/0ea827/32.png) [@daociyiyou](https://www.ruby-forum.com/u/daociyiyou)\ **Post date:** [July 15, 2010, 10:08pm UTC](https://www.ruby-forum.com/t/about-active-record-timestamps/191616/6 "2010-07-15T22:08:17Z")
> > > is going to contain date/time down to the second (or more). If you pass in > > > > > > > My talbe has another date type field which i want it to be local > > > > Product.find(:all, :conditions =\> [“DATE(created\_at) = ?”, selected\_date]) > > Will that have to do a calculation on every record to determine DATE? Yes. And as Christos said, you lose the use of the index. > If so would it be more efficient to specify a range for created\_at > instead (something like \>= selected\_date and \< selected\_date + 1.day)? > Particularly if there were an index on the column. d = Time.now Product.find(:all, :conditions =\> [“created\_at BETWEEN ? AND ?”, d.beginning\_of\_day, d.end\_of\_day]) would work… -philip ---
**Author:** ![daociyiyou](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/0ea827/32.png) [@daociyiyou](https://www.ruby-forum.com/u/daociyiyou)\ **Post date:** [July 16, 2010, 6:49am UTC](https://www.ruby-forum.com/t/about-active-record-timestamps/191616/7 "2010-07-16T06:49:52Z")
On Thu, Jul 15, 2010 at 12:09 PM, Rob B. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > Try: > > Product.find(:all, :conditions =\> [“DATE(created\_at) = ?”, selected\_date]) Note: this makes an assumption about what DB you’re using – e.g. Oracle has no such function and will throw an error 🙂 ## FWIW, Hassan S. ------------------------ removed\_email\_address@domain.invalid twitter: @hassan ---
**Author:** ![daociyiyou](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/0ea827/32.png) [@daociyiyou](https://www.ruby-forum.com/u/daociyiyou)\ **Post date:** [July 16, 2010, 10:36am UTC](https://www.ruby-forum.com/t/about-active-record-timestamps/191616/8 "2010-07-16T10:36:10Z")
Thank you! it make me confident.