当我启动rails console并想要测试我刚刚创建的模型模板时，rails console无法创建我的新模型实例。
yellow:maw thierry$ rails console
Running via Spring preloader in process 17717
Loading development environment (Rails 5.1.0)
>> Account.create(name: "John Doe", email: "john.doe@example.com", password: "1234ABCD", password_confirmation: "1234ABCD")
ActiveRecord::StatementInvalid: PG::UndefinedTable: ERROR: relation "accounts" does not exist
LINE 8: WHERE a.attrelid = '"accounts"'::regclass
^
: SELECT a.attname, format_type(a.atttypid, a.atttypmod),
pg_get_expr(d.adbin, d.adrelid), a.attnotnull, a.atttypid, a.atttypmod,
c.collname, col_description(a.attrelid, a.attnum) AS comment
FROM pg_attribute a
LEFT JOIN pg_attrdef d ON a.attrelid = d.adrelid AND a.attnum = d.adnum
LEFT JOIN pg_type t ON a.atttypid = t.oid
LEFT JOIN pg_collation c ON a.attcollation = c.oid AND a.attcollation <> t.typcollation
WHERE a.attrelid = '"accounts"'::regclass
AND a.attnum > 0 AND NOT a.attisdropped
ORDER BY a.attnum
from (irb):1
>>
但是，使用＆＃34; rails db＆＃34;，在相同的环境（这里，开发）中执行ActiveRecord SQL请求给我这个输出：
yellow:maw thierry$ rails db
psql (9.6.2)
Type "help" for help.
maw_development=> SELECT a.attname, format_type(a.atttypid, a.atttypmod),
maw_development-> pg_get_expr(d.adbin, d.adrelid), a.attnotnull, a.atttypid, a.atttypmod,
maw_development-> c.collname, col_description(a.attrelid, a.attnum) AS comment
maw_development-> FROM pg_attribute a
maw_development-> LEFT JOIN pg_attrdef d ON a.attrelid = d.adrelid AND a.attnum = d.adnum
maw_development-> LEFT JOIN pg_type t ON a.atttypid = t.oid
maw_development-> LEFT JOIN pg_collation c ON a.attcollation = c.oid AND a.attcollation <> t.typcollation
maw_development-> WHERE a.attrelid = '"accounts"'::regclass
maw_development-> AND a.attnum > 0 AND NOT a.attisdropped
maw_development-> ORDER BY a.attnum;
attname | format_type | pg_get_expr | attnotnull | atttypid | atttypmod | collname | comment
-----------------+-----------------------------+--------------------------------------+------------+----------+-----------+----------+---------
id | bigint | nextval('accounts_id_seq'::regclass) | t | 20 | -1 | |
name | character varying | | f | 1043 | -1 | |
email | character varying | | f | 1043 | -1 | |
created_at | timestamp without time zone | | t | 1114 | -1 | |
updated_at | timestamp without time zone | | t | 1114 | -1 | |
password_digest | character varying | | f | 1043 | -1 | |
(6 rows)
maw_development=> SELECT a.attname, format_type(a.atttypid, a.atttypmod),
pg_get_expr(d.adbin, d.adrelid), a.attnotnull, a.atttypid, a.atttypmod,
c.collname, col_description(a.attrelid, a.attnum) AS comment
FROM pg_attribute a
LEFT JOIN pg_attrdef d ON a.attrelid = d.adrelid AND a.attnum = d.adnum
LEFT JOIN pg_type t ON a.atttypid = t.oid
LEFT JOIN pg_collation c ON a.attcollation = c.oid AND a.attcollation <> t.typcollation
WHERE a.attrelid = 'accounts'::regclass
AND a.attnum > 0 AND NOT a.attisdropped
ORDER BY a.attnum;
attname | format_type | pg_get_expr | attnotnull | atttypid | atttypmod | collname | comment
-----------------+-----------------------------+--------------------------------------+------------+----------+-----------+----------+---------
id | bigint | nextval('accounts_id_seq'::regclass) | t | 20 | -1 | |
name | character varying | | f | 1043 | -1 | |
email | character varying | | f | 1043 | -1 | |
created_at | timestamp without time zone | | t | 1114 | -1 | |
updated_at | timestamp without time zone | | t | 1114 | -1 | |
password_digest | character varying | | f | 1043 | -1 | |
(6 rows)
maw_development=>
所有迁移都已应用：
yellow:maw thierry$ rake db:migrate:status
database: maw_development
Status Migration ID Migration Name
--------------------------------------------------
up 20170505175757 Create enterprises
up 20170507120815 Create accounts
up 20170507170408 Add index to users email
up 20170507172846 Add password digest to users
yellow:maw thierry$
就像你能看到的那样，我已经执行了两次请求：
有人遇到过这个错误吗？你是如何解决它的？
提前感谢您的帮助。
上下文
在模型目录中：
yellow:maw thierry$ ls -al app/models/
total 24
drwxr-xr-x 6 thierry staff 204 7 mai 14:08 .
drwxr-xr-x 10 thierry staff 340 5 mai 16:23 ..
-rw-r--r--@ 1 thierry staff 531 8 mai 12:44 account.rb
-rw-r--r-- 1 thierry staff 78 5 mai 16:23 application_record.rb
drwxr-xr-x 3 thierry staff 102 5 mai 16:23 concerns
-rw-r--r--@ 1 thierry staff 161 7 mai 18:41 enterprise.rb
yellow:maw thierry$
account.rb的内容：
yellow:maw thierry$ cat app/models/account.rb
class Account < ApplicationRecord
before_save { email.downcase! }
validates :name, presence: true, length: { maximum: 250 }
VALID_EMAIL_REGEX = /\A[\w+\-.]+@[a-z\d\-]+(\.[a-z\d\-]+)*\.[a-z]+\z/i
validates :email, presence: true, length: { maximum: 255 }, format: { with: VALID_EMAIL_REGEX }, uniqueness: { case_sensitive: false }
has_secure_password
#This validation must be put after has_secure_password in order for the password field to be defined.
validates :password, presence: true, length: { minimum: 6 }
end
yellow:maw thierry$
答案 0 :(得分：1)
结果是：
yellow:maw thierry$ rails console
Running via Spring preloader in process 22940
Loading development environment (Rails 5.1.0)
>> Account.create(name: "John Doe", email: "john.doe@example.com", password: "1234ABCD", password_confirmation: "1234ABCD")
(0.1ms) BEGIN
Account Exists (61.2ms) SELECT 1 AS one FROM "accounts" WHERE LOWER("accounts"."email") = LOWER($1) LIMIT $2 [["email", "john.doe@example.com"], ["LIMIT", 1]]
SQL (0.5ms) INSERT INTO "accounts" ("name", "email", "created_at", "updated_at", "password_digest") VALUES ($1, $2, $3, $4, $5) RETURNING "id" [["name", "John Doe"], ["email", "john.doe@example.com"], ["created_at", "2017-05-09 08:14:29.093633"], ["updated_at", "2017-05-09 08:14:29.093633"], ["password_digest", "$2a$10$3rCS7ynWP1r8VuPRDyQmOe0Czpm6ingOX16I6./s9a5TjUxnkPSzu"]]
(40.5ms) COMMIT
=> #<Account id: 1, name: "John Doe", email: "john.doe@example.com", created_at: "2017-05-09 08:14:29", updated_at: "2017-05-09 08:14:29", password_digest: "$2a$10$3rCS7ynWP1r8VuPRDyQmOe0Czpm6ingOX16I6./s9a5...">
>>