时间戳属性为零
Timestamp attributes are nil
我有 2 个模型，Microspost 和 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: "example@railstutorial.org",
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
但是当我使用 Faker 创建 Microposts 时，created_at 和 updated_at 属性在 Rails 中是 nil 而不是在 posgresql 中安慰。这让我很困惑，我不知道如何解决。
此外，当我手动创建 post 时，created_at 属性不为零。有人可以告诉我发生了什么事吗？
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 (, , , ) 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
当然，在我的 Posgresql 控制台中，您可以看到 microposts 实际上有时间戳。
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:
Faker 创建的 Micropost 有 nil 个时间戳。但是我自己创建的 Microposts 有一个有效的时间戳。
这来自 Faker 创建的微post（前 300 微post秒）
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" = 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
在深入了解您的申请后，我发现您的 config/application.rb:
中有这一行
config.active_record.default_timezone = 'Warsaw'
如果您希望使用 UTC，config.active_record.default_timezone 需要 :utc，如果您希望使用 config.time_zone 中的时区，则需要 :local。在本地，当我将其设置为 :local 时，我得到：
>> 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>
当设置为 :utc 时，我得到：
>> 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>
我自己可能会错过这个，但我去挖掘文档是因为配置 "just didn't look right™."
相关文档可以在section 3.6 of the Rails guide under Configuring Active Record.
中找到
我有 2 个模型，Microspost 和 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: "example@railstutorial.org",
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
但是当我使用 Faker 创建 Microposts 时，created_at 和 updated_at 属性在 Rails 中是 nil 而不是在 posgresql 中安慰。这让我很困惑，我不知道如何解决。
此外，当我手动创建 post 时，created_at 属性不为零。有人可以告诉我发生了什么事吗？
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 (, , , ) 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
当然，在我的 Posgresql 控制台中，您可以看到 microposts 实际上有时间戳。
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 有 nil 个时间戳。但是我自己创建的 Microposts 有一个有效的时间戳。
这来自 Faker 创建的微post（前 300 微post秒）
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" = 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
在深入了解您的申请后，我发现您的 config/application.rb:
config.active_record.default_timezone = 'Warsaw'
config.active_record.default_timezone 需要 :utc，如果您希望使用 config.time_zone 中的时区，则需要 :local。在本地，当我将其设置为 :local 时，我得到：
>> 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>
当设置为 :utc 时，我得到：
>> 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>
我自己可能会错过这个，但我去挖掘文档是因为配置 "just didn't look right™."
相关文档可以在section 3.6 of the Rails guide under Configuring Active Record.
中找到