rake db:create 使用 postgresql 抛出“数据库不存在”错误

Question

我在 Debian 7 下使用带有 postgresql 9.1 的 rails 4.1.5，但我无法在我的开发环境中创建数据库。当我跑步时

bin/rake db:create

我明白了

home/rs/.rvm/gems/ruby-2.1.2/gems/activerecord-4.1.5/lib/active_record/connection_adapters/postgresql_adapter.rb:898:in `rescue in connect': FATAL:  database "direct-dev" does not exist
Run `$ bin/rake db:create db:migrate` to create your database (ActiveRecord::NoDatabaseError)
from /home/rs/.rvm/gems/ruby-2.1.2/gems/activerecord-4.1.5/lib/active_record/connection_adapters/postgresql_adapter.rb:888:in `connect'
from ...

我正在尝试创建数据库，因此它自然不存在。但是 rails 应该创建它...这是我的 config/database.yml：

default: &default
  adapter: postgresql
  encoding: unicode
  pool: 5

development:
  <<: *default
  database: direct-dev

这是 postgresql 日志的一部分：

2014-09-01 19:30:40 CEST LOG:  connection received: host=[local]
2014-09-01 19:30:40 CEST LOG:  connection authorized: user=rs database=direct-dev
2014-09-01 19:30:40 CEST FATAL:  database "direct-dev" does not exist

你有什么建议吗？我已经在这里待了一个多小时，仍然无法理解为什么会这样......

谢谢！

Answer 1

Rails 4.1 ships with spring preloader，和

新的 Rails 4.1 应用程序将附带“弹性化”的 binstub。这意味着 bin/rails 和 bin/rake 将自动利用预加载的 spring 环境。

这意味着“springified”bin/rake 将尝试预加载应用程序，进而尝试运行初始化程序，从而导致您看到的问题。

要修复/解决此问题，您需要在没有 spring 的情况下运行初始设置 rake 任务。实现这一目标的一种方法是使用 bundler 运行它：

bundle exec rake db:create

Answer 2

我发现了问题...

这与 Rails 初始化程序有关：Rails 似乎在执行 bin/rake db:create 之前加载了所有初始化程序。

而且，在这个特定的应用程序中，有一些自定义初始化器依赖于 ActiveRecord 模型（反过来，它依赖于正在创建的、可用的数据库以及对应的表）。

因此，rake 永远不会真正执行任务，它在执行初始化程序时会失败。如果我仔细阅读了完整的错误消息日志，我应该知道。这是完整的日志（见下文，粗体，违规行）：

/home/rs/.rvm/gems/ruby-2.1.2/gems/activerecord-4.1.5/lib/active_record/connection_adapter/postgresql_adapter.rb:898:in `rescue in connect'：致命：数据库“ds-dev “ 不存在 运行`$ bin/rake db:create db:migrate`来创建你的数据库（ActiveRecord::NoDatabaseError） 来自 /home/rs/.rvm/gems/ruby-2.1.2/gems/activerecord-4.1.5/lib/active_record/connection_adapters/postgresql_adapter.rb:888:in `connect' 来自/home/rs/.rvm/gems/ruby-2.1.2/gems/activerecord-4.1.5/lib/active_record/connection_adapter/postgresql_adapter.rb:568:in `initialize' 来自 /home/rs/.rvm/gems/ruby-2.1.2/gems/activerecord-4.1.5/lib/active_record/connection_adapters/postgresql_adapter.rb:41:in `new' 来自/home/rs/.rvm/gems/ruby-2.1.2/gems/activerecord-4.1.5/lib/active_record/connection_adapters/postgresql_adapter.rb:41:in `postgresql_connection' 来自 /home/rs/.rvm/gems/ruby-2.1.2/gems/activerecord-4.1.5/lib/active_record/connection_adapters/abstract/connection_pool.rb:435:in `new_connection' 来自 /home/rs/.rvm/gems/ruby-2.1.2/gems/activerecord-4.1.5/lib/active_record/connection_adapters/abstract/connection_pool.rb:445:in `checkout_new_connection' 来自 /home/rs/.rvm/gems/ruby-2.1.2/gems/activerecord-4.1.5/lib/active_record/connection_adapters/abstract/connection_pool.rb:416:in `acquire_connection' 来自 /home/rs/.rvm/gems/ruby-2.1.2/gems/activerecord-4.1.5/lib/active_record/connection_adapters/abstract/connection_pool.rb:351:in `block in checkout' 来自 /home/rs/.rvm/rubies/ruby-2.1.2/lib/ruby/2.1.0/monitor.rb:211:in `mon_synchronize' 来自 /home/rs/.rvm/gems/ruby-2.1.2/gems/activerecord-4.1.5/lib/active_record/connection_adapters/abstract/connection_pool.rb:350:in `checkout' 来自 /home/rs/.rvm/gems/ruby-2.1.2/gems/activerecord-4.1.5/lib/active_record/connection_adapters/abstract/connection_pool.rb:265:in `block in connection' 来自 /home/rs/.rvm/rubies/ruby-2.1.2/lib/ruby/2.1.0/monitor.rb:211:in `mon_synchronize' 来自 /home/rs/.rvm/gems/ruby-2.1.2/gems/activerecord-4.1.5/lib/active_record/connection_adapters/abstract/connection_pool.rb:264:in `connection' 来自/home/rs/.rvm/gems/ruby-2.1.2/gems/activerecord-4.1.5/lib/active_record/connection_adapters/abstract/connection_pool.rb:541:in `retrieve_connection' 来自 /home/rs/.rvm/gems/ruby-2.1.2/gems/activerecord-4.1.5/lib/active_record/connection_handling.rb:113:in `retrieve_connection' 来自 /home/rs/.rvm/gems/ruby-2.1.2/gems/activerecord-4.1.5/lib/active_record/connection_handling.rb:87:in `connection' 来自 /home/rs/.rvm/gems/ruby-2.1.2/gems/activerecord-4.1.5/lib/active_record/model_schema.rb:209:in `table_exists?' 来自 /home/rs/pr/ds/app/models/property.rb:32:in `get' 来自 /home/rs/pr/ds/config/initializers/custom/setup_mail.rb:3:in `' 来自 /home/rs/.rvm/gems/ruby-2.1.2/gems/activesupport-4.1.5/lib/active_support/dependencies.rb:241:in `load' 来自 /home/rs/.rvm/gems/ruby-2.1.2/gems/activesupport-4.1.5/lib/active_support/dependencies.rb:241:in `block in load' 来自 /home/rs/.rvm/gems/ruby-2.1.2/gems/activesupport-4.1.5/lib/active_support/dependencies.rb:232:in `load_dependency' 来自 /home/rs/.rvm/gems/ruby-2.1.2/gems/activesupport-4.1.5/lib/active_support/dependencies.rb:241:in `load' 来自 /home/rs/.rvm/gems/ruby-2.1.2/gems/railties-4.1.5/lib/rails/engine.rb:648:in `block in load_config_initializer' 来自 /home/rs/.rvm/gems/ruby-2.1.2/gems/activesupport-4.1.5/lib/active_support/notifications.rb:161:in `instrument' 来自 /home/rs/.rvm/gems/ruby-2.1.2/gems/railties-4.1.5/lib/rails/engine.rb:647:in `load_config_initializer' 来自 /home/rs/.rvm/gems/ruby-2.1.2/gems/railties-4.1.5/lib/rails/engine.rb:612:in `block (2 levels) in ' 来自 /home/rs/.rvm/gems/ruby-2.1.2/gems/railties-4.1.5/lib/rails/engine.rb:611:in `each' 来自 /home/rs/.rvm/gems/ruby-2.1.2/gems/railties-4.1.5/lib/rails/engine.rb:611:in `block in' 来自 /home/rs/.rvm/gems/ruby-2.1.2/gems/railties-4.1.5/lib/rails/initializable.rb:30:in `instance_exec' 来自 /home/rs/.rvm/gems/ruby-2.1.2/gems/railties-4.1.5/lib/rails/initializable.rb:30:in `run' 来自 /home/rs/.rvm/gems/ruby-2.1.2/gems/railties-4.1.5/lib/rails/initializable.rb:55:in `block in run_initializers' 来自 /home/rs/.rvm/rubies/ruby-2.1.2/lib/ruby/2.1.0/tsort.rb:226:in `block in tsort_each' 来自 /home/rs/.rvm/rubies/ruby-2.1.2/lib/ruby/2.1.0/tsort.rb:348:in `block (2 levels) in each_strongly_connected_component' 来自 /home/rs/.rvm/rubies/ruby-2.1.2/lib/ruby/2.1.0/tsort.rb:418:in `block (2 levels) in each_strongly_connected_component_from' 来自/home/rs/.rvm/rubies/ruby-2.1.2/lib/ruby/2.1.0/tsort.rb:427:in `each_strongly_connected_component_from' 来自 /home/rs/.rvm/rubies/ruby-2.1.2/lib/ruby/2.1.0/tsort.rb:417:in `block in each_strongly_connected_component_from' 来自 /home/rs/.rvm/gems/ruby-2.1.2/gems/railties-4.1.5/lib/rails/initializable.rb:44:in `each' 来自 /home/rs/.rvm/gems/ruby-2.1.2/gems/railties-4.1.5/lib/rails/initializable.rb:44:in `tsort_each_child' 来自 /home/rs/.rvm/rubies/ruby-2.1.2/lib/ruby/2.1.0/tsort.rb:411:in `call' 来自/home/rs/.rvm/rubies/ruby-2.1.2/lib/ruby/2.1.0/tsort.rb:411:in `each_strongly_connected_component_from' 来自 /home/rs/.rvm/rubies/ruby-2.1.2/lib/ruby/2.1.0/tsort.rb:347:in `block in each_strongly_connected_component' 来自 /home/rs/.rvm/rubies/ruby-2.1.2/lib/ruby/2.1.0/tsort.rb:345:in `each' 来自 /home/rs/.rvm/rubies/ruby-2.1.2/lib/ruby/2.1.0/tsort.rb:345:in `call' 来自 /home/rs/.rvm/rubies/ruby-2.1.2/lib/ruby/2.1.0/tsort.rb:345:in `each_strongly_connected_component' 来自 /home/rs/.rvm/rubies/ruby-2.1.2/lib/ruby/2.1.0/tsort.rb:224:in `tsort_each' 来自 /home/rs/.rvm/rubies/ruby-2.1.2/lib/ruby/2.1.0/tsort.rb:205:in `tsort_each' 来自 /home/rs/.rvm/gems/ruby-2.1.2/gems/railties-4.1.5/lib/rails/initializable.rb:54:in `run_initializers' 来自 /home/rs/.rvm/gems/ruby-2.1.2/gems/railties-4.1.5/lib/rails/application.rb:300:in `initialize!' 来自 /home/rs/pr/ds/config/environment.rb:5:in `' 来自 /home/rs/.rvm/gems/ruby-2.1.2/gems/activesupport-4.1.5/lib/active_support/dependencies.rb:247:in `require' 来自 /home/rs/.rvm/gems/ruby-2.1.2/gems/activesupport-4.1.5/lib/active_support/dependencies.rb:247:in `block in require' 来自 /home/rs/.rvm/gems/ruby-2.1.2/gems/activesupport-4.1.5/lib/active_support/dependencies.rb:232:in `load_dependency' 来自 /home/rs/.rvm/gems/ruby-2.1.2/gems/activesupport-4.1.5/lib/active_support/dependencies.rb:247:in `require' 来自 /home/rs/.rvm/gems/ruby-2.1.2/gems/spring-1.1.3/lib/spring/application.rb:92:in `preload' 来自 /home/rs/.rvm/gems/ruby-2.1.2/gems/spring-1.1.3/lib/spring/application.rb:140:in `serve' 来自 /home/rs/.rvm/gems/ruby-2.1.2/gems/spring-1.1.3/lib/spring/application.rb:128:in `block in run' 来自 /home/rs/.rvm/gems/ruby-2.1.2/gems/spring-1.1.3/lib/spring/application.rb:122:in `loop' 来自 /home/rs/.rvm/gems/ruby-2.1.2/gems/spring-1.1.3/lib/spring/application.rb:122:in `run' 来自 /home/rs/.rvm/gems/ruby-2.1.2/gems/spring-1.1.3/lib/spring/application/boot.rb:18:in `' 来自 /home/rs/.rvm/rubies/ruby-2.1.2/lib/ruby/2.1.0/rubygems/core_ext/kernel_require.rb:55:in `require' 来自 /home/rs/.rvm/rubies/ruby-2.1.2/lib/ruby/2.1.0/rubygems/core_ext/kernel_require.rb:55:in `require' 从 -e:1:in `'

我将致力于重构代码，以消除初始化程序中的任何模型依赖项（我很确定这一定是一个非常糟糕的做法）。

Answer 3

您可以尝试运行此命令-

bin/rake db:create RAILS_ENV=development

或者这个命令-

bin/rake db:migrate RAILS_ENV=development

Answer 4

今天遇到了同样的问题（在 OS X 中）。

已解决：

psql -U postgres
CREATE ROLE rolename WITH CREATEDB LOGIN;

使用\du 检查它是否已创建。

使用\password rolename 为该用户/角色创建密码。

然后您可以使用bundle exec rake db:migrate 设置数据库

Answer 5

没有一个解决方案对我有用，但这对我有用。

$ brew services list
$ brew services restart postgresql

Answer 6

没有一个解决方案对我有用，但后来我看到一些答案提到预加载是问题的一部分。我意识到我有 config.eager_load = true 在config/environments/development.rb。我将其更改为 false 并解决了问题。

Answer 7

我看到两个问题，正如 is04 指出的，您的 database.yml 中可能至少需要一个 username 值。

您还需要创建 postgres 角色：

su - postgres
create role direct-dev with createdb login password 'password1'

Answer 8

我遇到了同样的问题，就我而言，我在 Answer 模型本身的验证中使用了 Answer.column_name。因为测试数据库已经在我的本地创建，所以 RAILS_ENV=test rails db:create 在本地运行良好，但在 CI/CD 管道中出现相同的错误

这是由于Rails在运行db:create命令之前加载了app/目录下的所有文件，而当时由于没有数据库存在Answer.column_names失败。

我用过这样的东西：

  validates_uniqueness_of :content, scope: (Answer.column_names - %w[id created_at updated_at]).map(&:to_sym), message: 'Duplicate answer'

这是错误的。然后我改为：

DUPLICATE_ANSWER_SCOPE = %i[content question_id session_id]
validates_uniqueness_of :content, scope: DUPLICATE_ANSWER_SCOPE, message: 'Duplicate answer'

Answer 9

这是我用于 rails 项目的 Dockerfile。 看看这部分：

CMD mkdir -p tmp/pids && \
    bundle exec rake db:create && \
    bundle exec rails db:migrate && \
    bundle exec rake db:seed && \
    bundle exec puma -C config/puma.rb

Bundler 2.1.4、ruby 2.7.2、rails 6.0.3 兼容。 Docker 撰写部分：

server:
    container_name: server
    build:
      context: Server
      dockerfile: Dockerfile
      args:
        ENV: 'development'
    restart: unless-stopped
    depends_on:
      - db
    env_file:
      - ./Server/.env
    ports:
      - '9090:3000'
    volumes:
      - ./Server:/app
      - ./Server/Docker/usr/.gemrc:/root/.gemrc
    networks:
      - app-network

FROM ruby:2.7.2-alpine3.12

# env and arg variables setup
ARG APP_HOME='/app'
ARG ENV
ENV RAILS_ENV=$ENV \
    RACK_ENV=$ENV \
    RAILS_ROOT=$APP_HOME

# timezone setup
RUN apk add --update tzdata && \
    cp /usr/share/zoneinfo/Europe/London /etc/localtime && \
    echo "Europe/London" > /etc/timezone

# building in tmp dir
WORKDIR /tmp
ADD Gemfile ./

#install dependencies (bundler 2.1.4, ruby 2.7.2, rails 6.0.3 compatible) 
RUN apk add --update --virtual runtime-deps postgresql-client nodejs libffi-dev readline sqlite xz && \
    apk add --virtual build-deps build-base openssl postgresql-dev libc-dev linux-headers libxml2-dev libxslt-dev readline-dev && \
    gem install bundler -v 2.1.4 && \
    bundle install --jobs=4 && \
    apk del build-deps

# /app
WORKDIR $APP_HOME

# create dbs if no such, migrate, seed, start
CMD mkdir -p tmp/pids && \
    bundle exec rake db:create && \
    bundle exec rails db:migrate && \
    bundle exec rake db:seed && \
    bundle exec puma -C config/puma.rb

Answer 10

这是我在每次部署时运行的命令列表（包括第一个）

//create pids folder if no yet
mkdir -p tmp/pids

//create dbs if no yet
bundle exec rake db:create

//run all new migrations
bundle exec rails db:migrate

//seed db with data if required
bundle exec rake db:seed

//start the server with config
bundle exec puma -C config/puma.rb