Question

My Job model has job_date field that is defined in the migration file like this:

create_table :jobs do |t|
  t.date "job_date", :null => false
  [...]
end

In my development environment (on Windows), when I do:

job = Job.new(:job_date => "17/04/2011")

everything works fine (i.e. the job_date is set properly), while when I do:

job = Job.new(:job_date => "04/17/2011")

job_date is set to nil.

I guess this is because the database (MySQL) expects to get the date in DD/MM/YYYY format.

The problem is that in my production environment, exactly the opposite occurs, i.e.:

job = Job.new(:job_date => "04/17/2011")

sets the ‘job_date` properly, while:

job = Job.new(:job_date => "17/04/2011")

sets it to nil.

How could I solve this inconsistency ?

Is there some way to config the database for specific date format (like DD/MM/YYYY) ?

Answer 1

It is not a database problem, but I think it is a problem with Date.parse method in Ruby. Infact when you call Job.new it is not saved to database only a new object of the model is created. I beleive Rails call Date.parse method to convert the string into date object and it gives a error for dd/mm/yyyy format in my machine

Date.parse("17/04/2011")
=> ArgumentError: invalid date
    from /usr/lib/ruby/1.8/date.rb:956:in `new_by_frags'
    from /usr/lib/ruby/1.8/date.rb:1000:in `parse'
    from (irb):3

I think Rails escape this error and gives nil for such values

job = Job.new(:job_date => "17/04/2011")
job.job_date
=> nil

job = Job.new(:job_date => "04/17/2011")
job.job_date
=> Sun, 17 Apr 2011

I guess your production environment’s results are same like my machine and your development machine’s Ruby, Date.parse may be working for the other format.

If you need to handle only one format(Either dd/mm/yyyy or mm/dd/yyyy), you can use Date.strptime to calculate the date before giving to database

job_date = Date.strptime("17/04/2011", "%d/%m/%Y") # or "%m/%d/%Y"
job = Job.new(:job_date => job_date)

This will work both in your production and development environment for one format.