其他的答案都不能让我完全满意。以下是Xubuntu 12.04.1 LTS上postgresql-9.1的工作原理。

Connect to the default database with user postgres: sudo -u postgres psql template1 Set the password for user postgres, then exit psql (Ctrl-D): ALTER USER postgres with encrypted password 'xxxxxxx'; Edit the pg_hba.conf file: sudo vim /etc/postgresql/9.1/main/pg_hba.conf and change "peer" to "md5" on the line concerning postgres: local      all     postgres     peer md5 To know what version of postgresql you are running, look for the version folder under /etc/postgresql. Also, you can use Nano or other editor instead of VIM. Restart the database : sudo /etc/init.d/postgresql restart (Here you can check if it worked with psql -U postgres). Create a user having the same name as you (to find it, you can type whoami): sudo createuser -U postgres -d -e -E -l -P -r -s <my_name> The options tell postgresql to create a user that can login, create databases, create new roles, is a superuser, and will have an encrypted password. The really important ones are -P -E, so that you're asked to type the password that will be encrypted, and -d so that you can do a createdb. Beware of passwords: it will first ask you twice the new password (for the new user), repeated, and then once the postgres password (the one specified on step 2). Again, edit the pg_hba.conf file (see step 3 above), and change "peer" to "md5" on the line concerning "all" other users: local      all     all     peer md5 Restart (like in step 4), and check that you can login without -U postgres: psql template1 Note that if you do a mere psql, it will fail since it will try to connect you to a default database having the same name as you (i.e. whoami). template1 is the admin database that is here from the start. Now createdb <dbname> should work.

其他的答案都不能让我完全满意。以下是Xubuntu 12.04.1 LTS上postgresql-9.1的工作原理。

Connect to the default database with user postgres: sudo -u postgres psql template1 Set the password for user postgres, then exit psql (Ctrl-D): ALTER USER postgres with encrypted password 'xxxxxxx'; Edit the pg_hba.conf file: sudo vim /etc/postgresql/9.1/main/pg_hba.conf and change "peer" to "md5" on the line concerning postgres: local      all     postgres     peer md5 To know what version of postgresql you are running, look for the version folder under /etc/postgresql. Also, you can use Nano or other editor instead of VIM. Restart the database : sudo /etc/init.d/postgresql restart (Here you can check if it worked with psql -U postgres). Create a user having the same name as you (to find it, you can type whoami): sudo createuser -U postgres -d -e -E -l -P -r -s <my_name> The options tell postgresql to create a user that can login, create databases, create new roles, is a superuser, and will have an encrypted password. The really important ones are -P -E, so that you're asked to type the password that will be encrypted, and -d so that you can do a createdb. Beware of passwords: it will first ask you twice the new password (for the new user), repeated, and then once the postgres password (the one specified on step 2). Again, edit the pg_hba.conf file (see step 3 above), and change "peer" to "md5" on the line concerning "all" other users: local      all     all     peer md5 Restart (like in step 4), and check that you can login without -U postgres: psql template1 Note that if you do a mere psql, it will fail since it will try to connect you to a default database having the same name as you (i.e. whoami). template1 is the admin database that is here from the start. Now createdb <dbname> should work.

这是我的解决方案:

su root
su postgres
psql

在MacOS中，我按照以下步骤使其工作。

首次安装时，请在安装完成后获取系统用户名。

$ cd ~
$ pwd
/Users/someuser
$ psql -d postgres -U someuser

现在您已经登录到系统，可以创建DB了。

postgres=# create database mydb;
CREATE DATABASE
postgres=# create user myuser with encrypted password 'pass123';
CREATE ROLE
postgres=# grant all privileges on database mydb to myuser;
GRANT

在Linux下，PostgresQL通常配置为允许根用户以postgres超级用户postgres的身份从shell(控制台或ssh)登录。

$ psql -U postgres

然后像往常一样创建一个新数据库:

CREATE ROLE myuser LOGIN password 'secret';
CREATE DATABASE mydatabase ENCODING 'UTF8' OWNER myuser;

这应该在不接触pg_hba.conf的情况下工作。如果你想通过网络使用一些GUI工具来做到这一点，那么你就需要修改pg_hba.conf。

Note: textdb is the database which you are going to explore with 'alex' user 

root@kalilinux:~# sudo su - postgres 
postgres=#  psql   
postgres=#  create database testdb;
postgres=#  create user alex with password 'alex';
postgres=# GRANT ALL PRIVILEGES ON DATABASE testdb TO alex;`enter code here`