psql: FATAL: role "postgres" does not exist

Question

I'm a postgres novice.

I installed the postgres.app for mac. I was playing around with the psql commands and I accidentally dropped the postgres database. I don't know what was in it.

I'm currently working on a tutorial: http://www.rosslaird.com/blog/building-a-project-with-mezzanine/

And I'm stuck at sudo -u postgres psql postgres

ERROR MESSAGE: psql: FATAL: role "postgres" does not exist

$ which psql

/Applications/Postgres.app/Contents/MacOS/bin/psql

This is what prints out of psql -l

                                List of databases
    Name    |   Owner    | Encoding | Collate | Ctype |     Access privileges     
------------+------------+----------+---------+-------+---------------------------
 user       | user       | UTF8     | en_US   | en_US | 
 template0  | user       | UTF8     | en_US   | en_US | =c/user                  +
            |            |          |         |       | user      =CTc/user      
 template1  | user       | UTF8     | en_US   | en_US | =c/user                  +
            |            |          |         |       | user      =CTc/user      
(3 rows)

So what are the steps I should take? Delete an everything related to psql and reinstall everything?

Thanks for the help guys!

Answer 1

NOTE: If you installed postgres using homebrew, see the comment from @user3402754 below.

Note that the error message does NOT talk about a missing database, it talks about a missing role. Later in the login process it might also stumble over the missing database.

But the first step is to check the missing role: What is the output within psql of the command \du ? On my Ubuntu system the relevant line looks like this:

                              List of roles
 Role name |            Attributes             | Member of 
-----------+-----------------------------------+-----------
 postgres  | Superuser, Create role, Create DB | {}        

If there is not at least one role with superuser , then you have a problem :-)

If there is one, you can use that to login. And looking at the output of your \l command: The permissions for user on the template0 and template1 databases are the same as on my Ubuntu system for the superuser postgres . So I think your setup simple uses user as the superuser. So you could try this command to login:

sudo -u user psql user

If user is really the DB superuser you can create another DB superuser and a private, empty database for him:

CREATE USER postgres SUPERUSER;
CREATE DATABASE postgres WITH OWNER postgres;

But since your postgres.app setup does not seem to do this, you also should not. Simple adapt the tutorial.

Answer 2

For MAC:

1. Install Homebrew
2. brew install postgres
3. initdb /usr/local/var/postgres
4. /usr/local/Cellar/postgresql/<version>/bin/createuser -s postgres or /usr/local/opt/postgres/bin/createuser -s postgres which will just use the latest version.
5. start postgres server manually: pg_ctl -D /usr/local/var/postgres start

---

To start server at startup

• mkdir -p ~/Library/LaunchAgents
• ln -sfv /usr/local/opt/postgresql/*.plist ~/Library/LaunchAgents
• launchctl load ~/Library/LaunchAgents/homebrew.mxcl.postgresql.plist

---

Now, it is set up, login using psql -U postgres -h localhost or use PgAdmin for GUI.

By default user postgres will not have any login password.

Check this site for more articles like this: https://medium.com/@Nithanaroy/installing-postgres-on-mac-18f017c5d3f7

Answer 3

The key is "I installed the postgres.app for mac." This application sets up the local PostgreSQL installation with a database superuser whose role name is the same as your login (short) name.

When Postgres.app first starts up, it creates the $USER database, which is the default database for psql when none is specified. The default user is $USER, with no password.

Some scripts (eg, a database backup created with pgdump on a Linux systsem) and tutorials will assume the superuser has the traditional role name of postgres .

You can make your local install look a bit more traditional and avoid these problems by doing a one time:

/Applications/Postgres.app/Contents/Versions/9.*/bin/createuser -s postgres

which will make those FATAL: role "postgres" does not exist go away.

Answer 4

createuser postgres --interactive

或仅使用以下命令创建超级用户 postgresl

createuser postgres -s

Answer 5

This happens when you run initdb with a user whose ID is not postgres , without specifying the postgres username with --username=postgres or -U postgres .

The database cluster is then created with the system's user account that you used to run initdb, and it is given superuser permissions.

To fix it, simply create a new user named postgres with the option --superuser using the createuser utility that comes with Postgres. The utility can be found in the Postgres' bin directory. eg

createuser --superuser postgres

If you have a custom hostname or port then be sure to set the appropriate options .

Don't forget to delete the other user account that was created for you by initdb.

Answer 6

如果您从 brew 安装了 postgres，请在终端中运行它：

/usr/local/opt/postgres/bin/createuser -s postgres

Answer 7

And if you are here in 2022 and wondering what works with the latest Postgres on the latest macOS (macOS Monterey )

follow this:

brew install postgresql
createuser -s postgres
brew services restart postgresql

Answer 8

First you need create a user:

sudo -u postgres createuser --superuser $USER

After you create a database:

sudo -u postgres createdb $USER

Change $USER to your system username.

You can see the the complete solutionhere .

Answer 9

I needed to unset $PGUSER :

$ unset PGUSER
$ createuser -s postgres

Answer 10

For me, this code worked:

/Applications/Postgres.app/Contents/Versions/9.4/bin/createuser -s postgres

it came from here: http://talk.growstuff.org/t/fatal-role-postgres-does-not-exist/216/4

Answer 11

If you installed postgres from Brew and are using an Apple Silicon (M1) mac , run this in your terminal:

/opt/homebrew/opt/postgresql/bin/createuser -s postgres

If you're using an Intel (x86) mac , run this in your terminal:

/usr/local/opt/postgres/bin/createuser -s postgres

Answer 12

在命令行上运行它应该修复它

/Applications/Postgres.app/Contents/Versions/9.4/bin/createdb <Mac OSX Username Here>

Answer 13

This worked for me

createuser -s postgres

note: I'm using mac catalina

Answer 14

This article helped me to solve same issue psql: FATAL: role “postgres” does not exist .

I am using mac, so I entered this command in terminal:

createuser -s postgres

And it worked for me.

Answer 15

If you're using docker, make sure you're NOT using POSTGRES_USER=something_else , as this variable is used by the standard image to know the name of the PostgreSQL admin user (default as postgres ).

In my case, I was using this variable with the intent to set another user to my specific database, but it ended up of course changing the main PostgreSQL user.

Answer 16

We have a db named postgres after brew install postgresql and brew services start postgresql . So we can open psql like this by default.

psql postgres

And then we can add users with any name like this in that psql console.

CREATE USER postgres

And if we want a super user, then we can add SUPERUSER at the end.

Answer 17

Dropping the postgres database doesn't really matter. This database is initially empty and its purpose is simply for the postgres user to have a kind of "home" to connect to, should it need one.

Still you may recreate it with the SQL command CREATE DATABASE postgres;

Note that the tutorial mentioned in the question is not written with postgres.app in mind. Contrary to PostgreSQL for Unix in general, postgres.app tries to look like a normal application as opposed to a service that would be run by a dedicated postgres user having different privileges than your normal user. postgres.app is run and managed by your own account.

So instead of this command: sudo -u postgres psql -U postgres , it would be more in the spirit of postgres.app to just issue: psql , which automatically connects to a database matching your users's name, and with a db account of the same name that happens to be superuser, so it can do anything permissions-wise.

Answer 18

这是唯一为我修复它的：

createuser -s -U $USER

Answer 19

For what it is worth, i have ubuntu and many packages installed and it went in conflict with it.

For me the right answer was:

sudo -i -u postgres-xc
psql

Answer 20

I've faced similar problem today, actually i was not sure what was the username. Here is the 2 thing, if you are under enterprise and don't have system admin access the postgres will create your enterprise username as the postgres admin username. If you install through Homebrew it will definitely happening. In that case simply run your psql service with brew and do an echo of the username

brew services start postgresql

then

echo $USER

You will see your username of the postgres user.

Answer 21

If you are experiencing this problem right after running a docker container try destroying the container and recreating it. That solved it for me:

docker-compose down
docker-compose up --force-recreate

This should recreate the db with postgresuser as default user

Answer 22

If you are a MAC (M1) user and installed the Postgres using HomeBrew then follow these steps:

1. Check your Postgres location using which psql
2. then run the command /opt/homebrew/bin/createuser -s postgres if the output for the first command is /opt/homebrew/bin/psql

The idea is to create a user named 'postgres' using the Postgres installation location. So you may need to change the command based on the location of your Postgres.

Answer 23

I don't think that sudo is needed here because psql -l returns a list of databases. This tells me that initdb was run under the user's current user, not under the postgres user.

You can just:

psql

And continue the tutorial.

I would suggest AH's general points of creating the postgres user and db because many applications may expect this to exist.

A brief explanation:

PostgreSQL will not run with administrative access to the operating system. Instead it runs with an ordinary user, and in order to support peer authentication (asking the OS who is trying to connect) it creates a user and db with the user that runs the initialization process. In this case it was your normal user.

Answer 24

On Ubuntu system, I purged the PostgreSQL and re-installed it. All the databases are restored. This solved the problem for me.

Advice - Take the backup of the databases to be on the safer side.

Answer 25

With a new mac (M1) and latest postgres (14.0) installed via homebrew, nothing helped me from this topic, but i just reinstalled postgres and it helped:

brew services stop postgresql
rm -rf /opt/homebrew/var/postgres/*
brew reinstall postgresql
initdb --locale=C -E UTF-8 /opt/homebrew/var/postgres
brew services restart postgresql

So, it's a miracle or something like that...

Then just:

psql -d postgres

Answer 26

I became stuck on this issue having executed brew services stop postgresql the day prior.
The day following: brew services start postgresql would not work. This is because as is shown when you install using homebrew. postgresql uses a launchd ... which loads when your computer is powered on.

resolution:
brew services start postgresql
Restart your computer.

Answer 27

The \du command return:

Role name = postgres@implicit_files

And that command postgres=# \password postgres return error:

ERROR: role "postgres" does not exist.

But that postgres=# \password postgres@implicit_files run fine.

Also after sudo -u postgres createuser -s postgres the first variant also work.

Answer 28

For m1 chips and homebrew version 3.4.9, the createuser is moved inside Cellar of the particular package. This worked for me /opt/homebrew/Cellar/postgresql@12/12.10_1/bin/createuser -s postgres

Answer 29

For m1 chips, if you have not installed postgresql package by homebrew, install it in terminal with:

brew install postgre

then create a username manually by:

/opt/homebrew/bin/createuser -s <username> 

your error is probably fixed; but if you occur the error

FATAL: database "databasename" does not exist

then you have to create your database manually by:

/opt/homebrew/bin/createdb -U <username>  <databasename>    

Answer 30

This document solved it for me: https://enrq.me/dev/2021/01/13/fix-role-postgres-does-not-exist/

The gist: run createuser -s postgres -U <os-username>

Answer 31

Context

I am adding an answer for a case I have not seen here, which is an edge case if you have multiple users on the same machine and the user who is trying to use postgres services is not the user who installed postgres on the machine.

What I have tried

Among other similar commands, for me all these commands failed:

createuser -s [your username]
# createuser: error: connection to server on socket "/tmp/.s.PGSQL.5432" failed: FATAL:  role "[your username]" does not exist

createuser -s postgres
# createuser: error: connection to server on socket "/tmp/.s.PGSQL.5432" failed: FATAL:  role "[your username]" does not exist

sudo -u postgres createuser --superuser [your username]
# sudo: unknown user: postgres
# sudo: error initializing audit plugin sudoers_audit

psql -U postgres
# psql: error: connection to server on socket "/tmp/.s.PGSQL.5432" failed: FATAL:  role "postgres" does not exist

Reason

The reason is because neither postgres role nor [your username] (aka whoami on your command line) are in postgres.

Solution

In such edge case I had to first login with the user who installed postgres:

sudo su - [username that installed postgres]

And then create a role for my new user:

createuser -s [your username]

Answer 32

psql -U debug -d dashboard_3

I had to specify the username and database name using the postgres:14 Docker container's terminal to be able to psql into the database.