How to insert timestamp into rails database-column

Question

I just started with RoR and have a question: How can I insert the current timestamp (or any type of time) into the model? Below you see the log function create.

def create
    @log = Log.new(params[:log])

    respond_to do |format|
      if @log.save
        format.html { redirect_to @log, notice: 'Log was successfully created.' }
        format.json { render json: @log, status: :created, location: @log }
      else
        format.html { render action: "new" }
        format.json { render json: @log.errors, status: :unprocessable_entity }
      end
    end
  end

Did you create the model using the rails generator?

Leo Correa
– Leo Correa

2013-03-15 00:33:30 +00:00
Commented Mar 15, 2013 at 0:33 — Leo Correa
– Leo Correa, Commented Mar 15, 2013 at 0:33

Community · Accepted Answer · 2015-09-26 23:47:18Z

25

The Rails model generator automatically creates created_at and updated_at datetime fields in the database for you. These fields are automatically updated when a record is created or updated respectively.

If you want to manually create a timestamp, add a datetime column (e.g. timestamp_field) to the database and use a before_save callback in your model.

class Log < ActiveRecord::Base
  before_save :generate_timestamp

  def generate_timestamp
    self.timestamp_field = DateTime.now
  end
end

edited Sep 26, 2015 at 23:47

CommunityBot

11 silver badge

answered Mar 15, 2013 at 0:36

Richard Brown

11.4k4 gold badges34 silver badges44 bronze badges

Sign up to request clarification or add additional context in comments.

4 Comments

zyrup Over a year ago

But I would insert the timestamp.

Don Kirkby Over a year ago

Don't you need to write self.timestamp_field = DateTime.now?

Chris Cirefice Over a year ago

@DonKirkby I believe so, as timestamp_field is currently defined as a local variable and as far as I know, ActiveRecord doesn't assume anything about variable names matching class attributes. So, one would need to preface with self as you have suggested, or make it an instance variable by prefacing with @. Then again, I've never encountered this scenario, just speculating.

Sollace May 2 at 14:27

Should you not use self.touch(:timestamp_field) instead?

Deepak Mahakale · Accepted Answer · 2016-11-08 09:24:21Z

5

Using the rails generator e.g rails generate model Log rails creates two timestamp fields automatically for you.

created_at and updated_at both of these fields will be filled by Rails when you create a new record doing Log.new then save on that record or Log.create The updated_at field gets updated only when you update the record's attributes or when you use the method touch on an instance of the model.

Now, if you wanted to create another field with the timestamp type you could make a migration that adds a column to your model like this

rails generate migration add_some_timestamp_field_to_logs my_timestamp_field:timestamp

This will generate a migration that will add a column named my_timestamp_field with a timestamp type, just like the created_at and updated_at

edited Nov 8, 2016 at 9:24

Deepak Mahakale

23.8k10 gold badges73 silver badges94 bronze badges

answered Mar 15, 2013 at 0:37

Leo Correa

20k2 gold badges56 silver badges71 bronze badges

Collectives™ on Stack Overflow

How to insert timestamp into rails database-column

2 Answers 2

4 Comments

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

4 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related