对于Windows(这对我很有帮助):

这就是我要参考的文档:如何重置PostgreSQL密码?

Open your cmd and go to C:\Program Files\PostgreSQL\12\data. This is usually the right path. You might have it stored somewhere else. Note that, if you have a different PostgreSQL version, there will be a different number. That doesn't matter. Find a pg_hba.conf file and copy it to somewhere else (that way you will have an unmodified version of this file, so you will be able to look at it after we make some changes) Open the pg_hba.conf file (not the backup, but the original) Find the multiple lines that start with host near the bottom of the file: host all all 127.0.0.1/32 md5 host all all ::1/128 md5 host replication all 127.0.0.1/32 md5 host replication all ::1/128 md5 Replace md5 with trust: host all all 127.0.0.1/32 trust host all all ::1/128 trust host replication all 127.0.0.1/32 trust host replication all ::1/128 trust Close this file Go to your search bar on windows and open Services app. Find postgres and restart it. Picture of services app Write cd.. in cmd and then cd bin. Your path should be C:\Program Files\PostgreSQL\12\bin Enter: psql -U postgres -h localhost Enter: ALTER USER postgres with password '<your new password>';Make sure that you include ; at the end “ALTER ROLE” should be displayed as an indication that the previous line was executed successfully Open original pg_hba.conf file and change back from trust to md5 Restart the server with Services app as before

Edit the file /etc/postgresql/<version>/main/pg_hba.conf and find the following line: local all postgres md5 Edit the line and change md5 at the end to trust and save the file Reload the postgresql service sudo service postgresql reload This will load the configuration files. Now you can modify the postgres user by logging into the psql shell psql -U postgres Update the postgres user's password alter user postgres with password 'secure-passwd-here'; Edit the file /etc/postgresql/<version>/main/pg_hba.conf and change trust back to md5 and save the file Reload the postgresql service sudo service postgresql reload Verify that the password change is working psql -U postgres -W

如果你在Windows上，你可以直接运行

net user postgres postgres

并以postgres/postgres用户/密码登录PostgreSQL。

当从命令行连接到PostgreSQL时，不要忘记添加-h localhost作为命令行参数。如果不是，PostgreSQL将尝试使用PEER认证模式进行连接。

下面显示了密码重置、使用PEER身份验证登录失败和使用TCP连接登录成功。

# sudo -u postgres psql

could not change directory to "/root"
psql (9.1.11)
Type "help" for help.

postgres=# \password
Enter new password:
Enter it again:
postgres=# \q

失败:

# psql -U postgres -W

Password for user postgres:
psql: FATAL:  Peer authentication failed for user "postgres"

使用-h localhost:

# psql -U postgres -W  -h localhost

Password for user postgres:
psql (9.1.11)
SSL connection (cipher: DHE-RSA-AES256-SHA, bits: 256)
Type "help" for help.

postgres=#

Find the file pg_hba.conf. It may be located, for example, in /etc/postgresql-9.1/pg_hba.conf. cd /etc/postgresql-9.1/ Back it up cp pg_hba.conf pg_hba.conf-backup Place the following line (as either the first uncommented line, or as the only one): For all occurrence of below (local and host) , except replication section if you don't have any it has to be changed as follow ,no MD5 or Peer authentication should be present. local all all trust Restart your PostgreSQL server (e.g., on Linux:) sudo /etc/init.d/postgresql restart If the service (daemon) doesn't start reporting in log file: local connections are not supported by this build you should change local all all trust to host all all 127.0.0.1/32 trust You can now connect as any user. Connect as the superuser postgres (note, the superuser name may be different in your installation. In some systems it is called pgsql, for example.) psql -U postgres or psql -h 127.0.0.1 -U postgres (note that with the first command you will not always be connected with local host) Reset the password ('replace my_user_name with postgres since you are resetting the postgres user) ALTER USER my_user_name with password 'my_secure_password'; Restore the old pg_hba.conf file as it is very dangerous to keep around cp pg_hba.conf-backup pg_hba.conf Restart the server, in order to run with the safe pg_hba.conf file sudo /etc/init.d/postgresql restart

关于pg_hba文件的进一步阅读:19.1。pg_hba.conf文件(正式文档)

我只是在Windows 10上有这个问题，在我的情况下，问题是我只是运行psql，它默认试图登录与我的Windows用户名(“内森”)，但没有PostgreSQL用户的名字，它没有告诉我。

所以解决方案是运行psql -U postgres而不是仅仅运行psql，然后我在安装时输入的密码就可以工作了。