Rails - Sep 2009 - Query for a specific day and month of a date

Hi all!

I have a table with the birthdays of users and I want my app to list
all users who birthdays today.

If today is 21/09/2009, I need all the rows which have the field
b_date 21/09.

How can I get that condition in ActiveRecord?
Should I try something like this:

@birthdays = Birthday.find(:all, :conditions => {:b_date.day =>
Date.today.day, :b_date.month => Date.today.month})

I''m a newbie so excuse me if this question is to much easy and excuse
my poor english too...

Thanks in advance.

On 21 Sep 2009, at 17:05, juanmac wrote:
>
> Hi all!
>
> I have a table with the birthdays of users and I want my app to list
> all users who birthdays today.
>
> If today is 21/09/2009, I need all the rows which have the field
> b_date 21/09.
>
> How can I get that condition in ActiveRecord?
> Should I try something like this:
>
> @birthdays = Birthday.find(:all, :conditions => {:b_date.day =>
> Date.today.day, :b_date.month => Date.today.month})
>
> I''m a newbie so excuse me if this question is to much easy and
excuse
> my poor english too...
>
You can''t do it quite like that. You need to turn what you want into  
something of the form

start_time <= b_date and b_date < end_time

(so start_date is probably the first second of today and end_time is  
the first second of tomorrow)

You can''t use the hash form of conditions for this.

Fred
> Thanks in advance.
> >

It depends how it'' stored in the Database.
If it is stored in a string of format ''MM/DD'', then
I''d probably do
something like this:

def find_birthdays
  mmdd = Date.today.to_s.gsub(''-'',
''/'')[5..9]
  @birthdays = Birthday.find :all, :conditions => [''b_date like
?'',
mmdd]
end

Just make sure the month and day are always two digits.
And there might be a smarter way to do it than using gsub, but I don''t 
know it off-hand.
-- 
Posted via http://www.ruby-forum.com/.

Thanks!

I did it that way Aldric. It seems to be the better way. I will have a
lots of rows in the database, so I wanted to boost the performance.
That''s why I want only to retrieve the specific day.

Thanks again! :D

On 21 sep, 21:29, Aldric Giacomoni
<rails-mailing-l...-ARtvInVfO7ksV2N9l4h3zg@public.gmane.org>
wrote:
> It depends how it'' stored in the Database.
> If it is stored in a string of format ''MM/DD'', then
I''d probably do
> something like this:
>
> def find_birthdays
>   mmdd = Date.today.to_s.gsub(''-'',
''/'')[5..9]
>   @birthdays = Birthday.find :all, :conditions => [''b_date like
?'',
> mmdd]
> end
>
> Just make sure the month and day are always two digits.
> And there might be a smarter way to do it than using gsub, but I
don''t
> know it off-hand.
> --
> Posted viahttp://www.ruby-forum.com/.

juanmac wrote:
> Thanks!
> 
> I did it that way Aldric. It seems to be the better way. I will have a
> lots of rows in the database, so I wanted to boost the performance.
> That''s why I want only to retrieve the specific day.
It''s not a good idea to store dates in the DB as strings.  You should 
store dates as dates in the DB.  SQL has date handling functions that 
you can use, so what you might want is something like :conditions => 
[''day(b_date) = :day and month(b_date) = :month'', {:day => 
Date.today.day, :month => Date.today.month}] .
> 
> Thanks again! :D
> 
> On 21 sep, 21:29, Aldric Giacomoni
<rails-mailing-l...-ARtvInVfO7ksV2N9l4h3zg@public.gmane.org>
Best,
--
Marnen Laibow-Koser
http://www.marnen.org
marnen-sbuyVjPbboAdnm+yROfE0A@public.gmane.org
-- 
Posted via http://www.ruby-forum.com/.

>
> It''s not a good idea to store dates in the DB as strings.  You
should
> store dates as dates in the DB.  SQL has date handling functions that
> you can use,
I agree with Marnen in this point. If you use a table "birthdays" for
storing the birthdays for users having fields
      user_id => :integer
      date => :date

then i think its better to use named_scope. As i said, if your model
name is Birthday then define a named_scope as
      named_scope :of_day, lambda { |date| {:conditions => { :day =>
date } } }

And call it like
      Birthday.of_day(Date.today)

That will generate a single query like following
      SELECT * FROM `birthdays ` WHERE (`birthdays `.`date`
''2009-09-22'')

This will give you a reusable and readable way you can apply for any
other days if you want.
Hope this will help :D

Thank you.

samiron
http://samironpaul.blogspot.com
http://www.scrumpad.com

Marnen Laibow-Koser wrote:
> 
> It''s not a good idea to store dates in the DB as strings.  You
should
> store dates as dates in the DB.  SQL has date handling functions that 
> you can use, so what you might want is something like :conditions => 
> [''day(b_date) = :day and month(b_date) = :month'', {:day
=>
> Date.today.day, :month => Date.today.month}] .
> 
Marnen is right, mind you. If you store a year with it, you have access 
to all the Rails date manipulation methods, as well as those of the 
database. It''s better practice, and more convenient.
-- 
Posted via http://www.ruby-forum.com/.