postgresql “PG::UndefinedTable：错误：关系不存在”具有正确的 Rails 命名和约定
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"PG::UndefinedTable: ERROR: relation does not exist" with a correct Rails naming and convention
提问by Albert Català
I've read a lot of potsts like this, but all the solutions I've seen are in the nomenclature of the models, naming and Rails convention.
我读过很多这样的potsts，但我看到的所有解决方案都在模型的命名法、命名和Rails约定中。
Now I have this problem when I run for first time in production environment in PostgreSQL 9.1
现在我在 PostgreSQL 9.1 的生产环境中第一次运行时遇到了这个问题
rake db:migrate RAILS_ENV=production
or
或者
rake db:schema:load RAILS_ENV=production
I could create database without problems: rake db:create RAILS_ENV=production=>OK
我可以毫无问题地创建数据库：rake db:create RAILS_ENV=production=>好的
The error is
错误是
rake aborted!
PG::UndefinedTable: ERROR: relation "categories" does not exist
LINE 5: WHERE a.attrelid = '"categories"'::regclass
^
: SELECT a.attname, format_type(a.atttypid, a.atttypmod),
pg_get_expr(d.adbin, d.adrelid), a.attnotnull, a.atttypid, a.atttypmod
FROM pg_attribute a LEFT JOIN pg_attrdef d
ON a.attrelid = d.adrelid AND a.attnum = d.adnum
WHERE a.attrelid = '"categories"'::regclass
AND a.attnum > 0 AND NOT a.attisdropped
ORDER BY a.attnum
And the models follows all Rails naming convention. So that, I don't know what this error is telling me ?There is something else that can cause this error?
并且模型遵循所有 Rails 命名约定。所以，我不知道这个错误告诉我 什么？还有其他可能导致这个错误的东西吗？
The models:
型号：
class Category < ActiveRecord::Base
has_many :subcategories
end
class Subcategory < ActiveRecord::Base
belongs_to :category
end
shema.rb:
shema.rb:
ActiveRecord::Schema.define(version: nnnn) do
# These are extensions that must be enabled in order to support this database
enable_extension "plpgsql"
create_table "categories", force: true do |t|
t.string "name"
t.text "comments"
t.datetime "created_at"
t.datetime "updated_at"
t.decimal "amount_need_comments", precision: 6, scale: 2
t.decimal "amount", precision: 6, scale: 2
t.decimal "amount_per_unit", precision: 6, scale: 2
t.integer "teletrabajo", limit: 2, default: 0, null: false
t.decimal "amount_need_city", precision: 6, scale: 2
end
create_table "subcategories", force: true do |t|
t.string "name"
t.text "comments"
t.integer "category_id"
t.datetime "created_at"
t.datetime "updated_at"
t.decimal "amount_need_comments", precision: 6, scale: 2
t.decimal "amount", precision: 6, scale: 2
t.decimal "amount_per_unit", precision: 6, scale: 2
t.decimal "amount_need_city", precision: 6, scale: 2
end
And finally, I tried something like this, without success
最后，我尝试了这样的事情，但没有成功
inflections.rb
拐点.rb
ActiveSupport::Inflector.inflections do |inflect|
inflect.irregular 'category', 'categories'
inflect.irregular 'subcategory', 'subcategories'
inflect.plural 'category', 'categories'
inflect.plural 'subcategory', 'subcategories'
end
And remove the relationship of the models involved, like this:
并删除所涉及模型的关系，如下所示：
class ExpenseDetail < ActiveRecord::Base
# belongs_to :expense
# belongs_to :category
# belongs_to :subcategory
default_scope :order=>"id"
validate :expense_date...
...
...
回答by bmalets
I have the same problem and I found that in my migrations I don't have table names in plural form:
我有同样的问题，我发现在我的迁移中我没有复数形式的表名：
For example:
例如：
class CreatePosts ActiveRecord::Migration
def change
create_table :posts do |t|
t.string :source
t.string :destination
t.datetime :time
t.timestamps
end
end
end
I have create_table :post, but when I change it to create_table :posts.
It start working!!!!
我有create_table :post，但是当我将其更改为create_table :posts. 它开始工作！！！！
