安装Postgresql之后，创建用户 配置rails

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sudo su - postgres

psql

1 创建Postgresql新用户，devpg是用户名，密码也是devpg， 不是超级管理员，拥有创建数据库权限，登录权限，继承拥有角色权限

create user devpg with NOSUPERUSER CREATEDB NOCREATEROLE INHERIT LOGIN  PASSWORD 'devpg' ;

　　

2 du查看

postgres=# du
                                   List of roles
 Role name |                         Attributes                         | Member of 
-----------+------------------------------------------------------------+-----------
 devpg     | Create DB                                                  | {}
 postgres  | Superuser, Create role, Create DB, Replication, Bypass RLS | {}

3 配置rails  config/database.yml  ,注意host属性和port属性要填写

注意： 同时要安装 pg 这个gem , gem install pg

default: &default
  adapter: postgresql
  pool: <%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>
  timeout: 5000
  username: devpg
  password: devpg
  host: localhost
  port: 5432

development:
  <<: *default
  database: developmentpg

# Warning: The database defined as "test" will be erased and
# re-generated from your development database when you run "rake".
# Do not set this db to the same as development or production.
test:
  <<: *default
  database: testpg

production:
  <<: *default
  database: productionpg

　　

4 然后在rails目录的终端下 执行

rake db:setup