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。

将下面的代码添加到pg_hba.conf文件中。PostgreSQL的安装目录中会出现哪个

hostnossl    all          all            0.0.0.0/0  trust

它将开始工作。

pg_hba.conf (C:\Program Files\PostgreSQL\9.3\data)文件在给出这些答案后发生了变化。在Windows中，对我有用的是打开文件并将METHOD从md5更改为trust:

# TYPE  DATABASE        USER            ADDRESS                 METHOD

# IPv4 local connections:
host    all             all             127.0.0.1/32            trust
# IPv6 local connections:
host    all             all             ::1/128                 trust

然后，我使用pgAdmin III在没有密码的情况下登录，通过“文件→更改密码”菜单修改了用户postgres的密码。

Windows用户PostgreSQL最新版本(大于10):

到PostgreSQL安装位置，搜索pg_hba.conf，你会在..\postgres\data\pg_hba.conf中找到它。

用记事本打开这个文件，找到这行:

# TYPE  DATABASE        USER            ADDRESS                 METHOD

# IPv4 local connections:
host    all             all             127.0.0.1/32            md5
# IPv6 local connections:
host    all             all             ::1/128                 md5
#..

Change the method from *md5* to *trust*:

# TYPE  DATABASE        USER            ADDRESS                 METHOD

# IPv4 local connections:
host    all             all             127.0.0.1/32            trust
# IPv6 local connections:
host    all             all             ::1/128                 trust
# ...

现在转到你的SQL shell (PSQL)，让一切都为空，

Server [localhost]:
Database [postgres]:
Port [8000]:
Username [postgres]:

这次它不会要求你输入密码，你就可以登录了，

现在运行这一行:

  `ALTER USER yourusername WITH SUPERUSER`

现在您可以将\q留在外壳中。

再次进入“pg_hba.conf”文件，将“METHOD”从“trust”修改为“md5”并保存。

现在使用新用户和密码登录，可以检查\du的属性。

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

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)