Timestamp attributes are null

Question

I have 2 models, Microspost and User :

 class Micropost < ActiveRecord::Base belongs_to :user default_scope -> { order(created_at: :desc) } validates :user_id, presence: true validates :content, presence: true, length: { maximum: 140 } end class User < ActiveRecord::Base has_many :microposts, dependent: :destroy attr_accessor :remember_token, :activation_token, :reset_token before_save :downcase_email before_create :create_activation_digest validates :name, presence: true, length: { maximum: 50 } end 

seed.rb :

 User.create!(name: "Example User", email: " [e-mail] ", password: "foobar", password_confirmation: "foobar", admin: true, activated: true, activated_at: Time.zone.now) 99.times do |n| name = Faker::Name.name email = "example-#{n+1}@railstutorial.org" password = "password" User.create!(name: name, email: email, password: password, password_confirmation: password, activated: true, activated_at: Time.zone.now) end # Microposts users = User.order(:created_at).take(6) 50.times do content = Faker::Lorem.sentence(5) users.each { |user| user.microposts.create!(content: content) } end 

But when I used Faker to create Microposts, the created_at and updated_at nil attributes were in Rails, but NOT in the posgresql console. It confused me, and I don’t know how to fix it. Moreover, when I manually create a message, the created_at attribute is not zero. Can someone please tell me what is going on?

 2.1.5 :016 > m = Micropost.create!(content: "hello", user_id: User.first.id) User Load (0.6ms) SELECT "users".* FROM "users" ORDER BY "users"."id" ASC LIMIT 1 (0.2ms) BEGIN SQL (0.8ms) INSERT INTO "microposts" ("content", "user_id", "created_at", "updated_at") VALUES ($1, $2, $3, $4) RETURNING "id" [["content", "hello"], ["user_id", 1], ["created_at", "2015-01-13 08:07:38.584269"], ["updated_at", "2015-01-13 08:07:38.584269"]] (9.6ms) COMMIT => #<Micropost id: 301, content: "hello", user_id: 1, created_at: "2015-01-13 07:07:38", updated_at: "2015-01-13 07:07:38"> 2.1.5 :017 > m.created_at => Tue, 13 Jan 2015 08:07:38 CET +01:00 

And, of course, here, on my Posgresql console, you can see that there are timestamps on microsostats.

 railsdays_development=# \d+ microposts Table "public.microposts" Column | Type | Modifiers | Storage | Stats target | Description ------------+-----------------------------+---------------------------------------------------------+----------+--------------+------------- id | integer | not null default nextval('microposts_id_seq'::regclass) | plain | | content | text | | extended | | user_id | integer | | plain | | created_at | timestamp without time zone | not null | plain | | updated_at | timestamp without time zone | not null | plain | | Indexes: "microposts_pkey" PRIMARY KEY, btree (id) "index_microposts_on_user_id" btree (user_id) "index_microposts_on_user_id_and_created_at" btree (user_id, created_at) Has OIDs: no railsdays_development=# select * from microposts; id | content | user_id | created_at | updated_at -----+-----------------------------------------------------------------------------------+---------+----------------------------+---------------------------- 1 | Velit optio magni in modi distinctio. | 1 | 2015-01-13 06:48:48.212602 | 2015-01-13 06:48:48.212602 2 | Velit optio magni in modi distinctio. | 2 | 2015-01-13 06:48:48.216021 | 2015-01-13 06:48:48.216021 3 | Velit optio magni in modi distinctio. | 3 | 2015-01-13 06:48:48.218617 | 2015-01-13 06:48:48.218617 4 | Velit optio magni in modi distinctio. | 4 | 2015-01-13 06:48:48.221544 | 2015-01-13 06:48:48.221544 5 | Velit optio magni in modi distinctio. | 5 | 2015-01-13 06:48:48.223975 | 2015-01-13 06:48:48.223975 6 | Velit optio magni in modi distinctio. | 6 | 2015-01-13 06:48:48.226611 | 2015-01-13 06:48:48.226611 7 | Magni aliquid ut enim sunt aut. | 1 | 2015-01-13 06:48:48.22897 | 2015-01-13 06:48:48.22897 8 | Magni aliquid ut enim sunt aut. | 2 | 2015-01-13 06:48:48.23096 | 2015-01-13 06:48:48.23096 9 | Magni aliquid ut enim sunt aut. | 3 | 2015-01-13 06:48:48.232889 | 2015-01-13 06:48:48.232889 10 | Magni aliquid ut enim sunt aut. | 4 | 2015-01-13 06:4: 

Micropost, created by Faker, has nil timestamps. But the Microposts I create have a valid timestamp.

This is from a micropost created by Faker (the first 300 microcells)

 2.1.5 :021 > Micropost.count (0.6ms) SELECT COUNT(*) FROM "microposts" => 301 2.1.5 :022 > a = Micropost.find(2).created_at Micropost Load (0.6ms) SELECT "microposts".* FROM "microposts" WHERE "microposts"."id" = $1 ORDER BY "microposts"."created_at" DESC LIMIT 1 [["id", 2]] => nil 2.1.5 :023 > 

_create_microposts.rb :

 class CreateMicroposts < ActiveRecord::Migration def change create_table :microposts do |t| t.text :content t.references :user, index: true t.timestamps null: false end add_index :microposts, [:user_id, :created_at] end end 

Answer 1

After processing your application, I found that you have this line in config/application.rb :

config.active_record.default_timezone = 'Warsaw'

config.active_record.default_timezone expects either :utc if you want to use UTC, or :local if you expect it to use the time zone found in config.time_zone . Locally, when I set this to :local , I get:

 >> Micropost.first Micropost Load (1.0ms) SELECT "microposts".* FROM "microposts" ORDER BY "microposts"."created_at" DESC LIMIT 1 => #<Micropost id: 300, content: "Nemo fuga eveniet expedita consequatur.", user_id: 6, created_at: "2015-01-19 22:21:48", updated_at: "2015-01-19 22:21:48", picture: nil> 

When set to :utc , I get:

 >> Micropost.first Micropost Load (0.6ms) SELECT "microposts".* FROM "microposts" ORDER BY "microposts"."created_at" DESC LIMIT 1 => #<Micropost id: 300, content: "Nemo fuga eveniet expedita consequatur.", user_id: 6, created_at: "2015-01-19 16:21:48", updated_at: "2015-01-19 16:21:48", picture: nil> 

I probably would have missed this myself, but I went to dig the documents because the config "just didn't look right."

The relevant documentation can be found in the section of section 3.6 of the Rails manual in the section Configuring Active Recording.