Datetime field inserted is NULL

Rails
1

This is pretty baffling. I have the following model object:

create_table “activities”, :force => true do |t|
t.integer “user_id”, :limit => 11
t.datetime “created_at”
t.datetime “updated_at”
t.integer “location_id”, :limit => 11
t.datetime “event_date”
end

model/activity.rb:

class Activity < ActiveRecord::Base

belongs_to :User
belongs_to :Location

attr_accessor :event_date
attr_accessor :user
attr_accessor :location

end

my activities_controller.rb:

activity = Activity.new(params[:activity])

activity.event_date = Date.today

activity.user_id = current_user.id

activity.save

It throws an error b/c it’s trying to insert NULL for event_date in the
MYSQL database:
ActiveRecord::StatementInvalid (Mysql::Error: Column ‘event_date’ cannot
be null: INSERT INTO activities (update\ d_at, location_id, user_id, event_date, created_at)
VALUES(‘2008-07-30 05:16:00’, 1, 1, NULL, ‘2008-07-30
05:16:00’)):

I have no idea why. If I explicitly print out ‘activity.event_date.to_s’
is gives me the date of today.

If I remove the stipulation the “event_date” can be NULL it just insert
a NULL value.

thanks in advance for help

2

Hi Allen,

Allen W. wrote:

model/activity.rb:

end

This is definitely just a guess, but I’ve never seen attr_accessor used
on
an ActiveRecord::Base object coming from an MySQL table. I’d speculate
that
it may be overriding AR’s behavior somehow, but that’s definitely just a
guess. What happens if you delete that line from your model?

Bill

3

Looks like it fixed a few things. Yes I was confused in using the
“attr_*” declaration on an ActiveRecord::Base. Sometimes I wished rails
would throw a warning of some kind.

Thanks

Bill W. wrote:

Hi Allen,

Allen W. wrote:

model/activity.rb:

end

This is definitely just a guess, but I’ve never seen attr_accessor used
on
an ActiveRecord::Base object coming from an MySQL table. I’d speculate
that
it may be overriding AR’s behavior somehow, but that’s definitely just a
guess. What happens if you delete that line from your model?

Bill

4

You’re trying to set a datetime field to a Date object whereas Rails
would expect a Time object (like Time.now).

You already know you don’t need to (and shouldn’t) make attr_*
declarations for your model’s fields.

You also are using capitalized :User and :Location for your
belongs_to. This will fail. They should be lowercase. Also, if a user
has many activities you can say @activity =
current_user.activities.build(params[:activity]) and not have to set
the user_id manually.

I’m also not certain why you need a not null constraint in the
database. Better to use a validates_presence_of :event_date in the
model.

Rein H.
Hashrocket
http://reinh.com