Ruby-on-rails Postgresql 适配器 (pg)：无法连接到服务器
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Postgresql adapter (pg): could not connect to server
提问by sparkle
I get this error every this I run my Rails app (It cannot connect to my local Postgresql)
我每次运行 Rails 应用程序时都会收到此错误（它无法连接到我的本地 Postgresql）
/Users/leonardo/.rvm/gems/ruby-1.9.3-p362/gems/activerecord-3.2.11/lib/
active_record/connection_adapters/postgresql_adapter.rb:1208:in `initialize':
could not connect to server: No such file or directory (PG::Error)
Is the server running locally and accepting
connections on Unix domain socket "/var/pgsql_socket/.s.PGSQL.5432"?
I'm using Postgres.appthat it's correctly running.
我正在使用正确运行的Postgres.app。
If I run
如果我跑
$ psql
I can login properly to Postgresql console.
我可以正确登录到 Postgresql 控制台。
$ which psql
/Applications/Postgres.app/Contents/MacOS/bin/psql
Gemfile
文件
source 'https://rubygems.org'
ruby "1.9.3"
gem 'rails', '3.2.11'
gem "pg"
database.yml
数据库.yml
development:
adapter: postgresql
encoding: unicode
username: leonardo
password:
database: zapping
port: 5432
Postgresql(Console)
Postgresql（控制台）
$ psql
leonardo=# \l
回答by pjam
Try adding host: localhostto your database.yml. (Based on: https://stackoverflow.com/a/10793186/919641)
尝试添加host: localhost到您的 database.yml。（基于：https: //stackoverflow.com/a/10793186/919641）
回答by Craig Ringer
Your Pggem was compiled against the PostgreSQL libpq pre-installed in Mac OS X and you're using the psqlthat you installed in a newer version, or vice versa.
您的Pggem 是针对 Mac OS X 中预装的 PostgreSQL libpq 编译的，并且您使用的psql是在较新版本中安装的 PostgreSQL ，反之亦然。
This can be worked around by specifying a TCP/IP connection, by adding localhostto database.yml, but it's better to compile the Pggem against the libpqfor the server you're actually running. To do that, you should be able to set the PATHenvironment variable to the folder with the correct pg_configin it before compiling. In your case that'll be somewhere within Postgres.app.
这可以通过指定 TCP/IP 连接、添加localhost到 来解决database.yml，但最好Pg针对libpq您实际运行的服务器编译gem 。为此，您应该能够在编译之前将PATH环境变量设置为正确的文件夹pg_config。在您的情况下，它将在Postgres.app.
回答by Pradyumna Shembekar
If it does not work even after adding host: localhost, remove the postmaster.pid
如果添加后仍然不起作用host: localhost，请删除postmaster.pid
rm /usr/local/var/postgres/postmaster.pid
rm /usr/local/var/postgres/postmaster.pid
回答by BvuRVKyUVlViVIc7
you should add host: localhostto your db config...
你应该添加host: localhost到你的数据库配置...
回答by Mr. Rene
Since This was the first post that appeared in my search result, I have decided to post the updated fix for this. Since none of the above suggestion worked for me.
由于这是我的搜索结果中出现的第一篇文章，因此我决定为此发布更新的修复程序。由于上述建议都不适合我。
brew postgresql-upgrade-database
It upgraded postgresql data and moved my old version. I was on 9.6 instead of 10.4
它升级了 postgresql 数据并移动了我的旧版本。我在 9.6 而不是 10.4
Found the solution here
在这里找到了解决方案
回答by L. Stepanek
I had this same issue. You have to actually run / start postgres. Postgres must have stopped running on my computer recently, so I had to make sure it's running by starting the postgres server
我有同样的问题。您必须实际运行/启动 postgres。Postgres 最近一定在我的电脑上停止运行了，所以我必须通过启动 postgres 服务器来确保它正在运行
postgres -D /usr/local/var/postgres
Then the following commands (which were causing me the same error you had) all worked:
然后以下命令（这导致我遇到了与您相同的错误）都有效：
bundle exec rake db:create db:migrate
bundle exec rspec
回答by Jared Menard
I had this issue. One of the comments here helped me fix the issue.
我有这个问题。这里的评论之一帮助我解决了这个问题。
Thanks, this answer helped me fix it. The steps I took were simple: 1) gem uninstall pg, 2) bundle install, done. – haslo Dec 3 '13 at 20:27
谢谢，这个答案帮助我解决了这个问题。我采取的步骤很简单：1）gem uninstall pg，2）bundle install，完成。– 哈斯洛 2013 年 12 月 3 日 20:27
gem uninstall pg
bundle install
回答by paneer_tikka
I had the same problem on a Mac. Turns out that the psql I had on my path wasn't working correctly. Try launching psql by typing:
我在 Mac 上遇到了同样的问题。原来我的路径上的 psql 无法正常工作。尝试通过键入以下内容启动 psql：
~/projects/some_project/project-rails$ psql
psql: could not connect to server: No such file or directory
Is the server running locally and accepting
connections on Unix domain socket "/var/pgsql_socket/.s.PGSQL.5432"?
If you see this, it indicates the psql binary on your path is attempting to connect using socket and unable to do so (for whatever reason). Since I had already downloaded pgadminand it was connecting fine, I knew it wasn't an issue with the server.
如果您看到这一点，则表明您路径上的 psql 二进制文件正在尝试使用套接字进行连接，但无法连接（无论出于何种原因）。由于我已经下载了pgadmin并且连接正常，我知道这不是服务器的问题。
Fixed itby adding the right version of pgsql to my PATH:
通过将正确版本的 pgsql 添加到我的 PATH 来修复它：
export PATH=/Applications/Postgres.app/Contents/MacOS/bin:$PATH
Now psql (and rails) are happy!
现在 psql（和 rails）很高兴！
回答by the-teacher
find / -name 'postgresql.conf'
find / -name 'postgresql.conf'
netstat -an | grep 5432 # => /tmp/.s.PGSQL.5432
netstat -an | grep 5432 # => /tmp/.s.PGSQL.5432
vi /Users/admin/Library/Application\ Support/Postgres93/var/postgresql.conf
vi /Users/admin/Library/Application\ Support/Postgres93/var/postgresql.conf
FROM:unix_socket_directories = '/tmp'
来自：unix_socket_directories = '/tmp'
TO:unix_socket_directories = '/var/pgsql_socket'
至：unix_socket_directories = '/var/pgsql_socket'
sudo mkdir /var/pgsql_socket
须藤 mkdir /var/pgsql_socket
sudo chmod 777 /var/pgsql_socket
须藤 chmod 777 /var/pgsql_socket
回答by jmontross
For heroku this is all you need.
对于heroku，这就是你所需要的。
heroku addons:create heroku-postgresql
production:
adapter: postgresql
encoding: unicode
host: localhost
# For details on connection pooling, see rails configuration guide
# http://guides.rubyonrails.org/configuring.html#database-pooling
pool: 5
