After installing postgresql, I tried it out, typing createdb mydb, like it's written in the documentation. Then the following error occured:
createdb: could not connect to database postgres: FATAL: role "xxx" does not exist
I studied the documentation, where is said:
You will need to become the operating system user under which PostgreSQL was installed (usually postgres) to create the first user account
I tried this by accessing psql (in my case with sudo -u postgres psql, using Ubuntu 12.10).
But then what should I do?
if the db is owned by user postgres you can do the following
createdb -U postgres dbname
since by default postgresql will trust connections from localhost.
su - postgres
and after you have been logged in:
createdb mydb
Related
I'm having trouble using PostgreSQL. I have recently installed this version (13+223.pgdg20.04+1) of postgresql package in ubuntu 20.04.
I'm trying to run psql command, but I get the following error:
psql: error: FATAL: role "my_username" does not exist
I have tried to create a new user with createuser me, but I get the following error:
createuser: error: could not connect to database template1: FATAL: role "my_username" does not exist
I have tried also forcing the postgres user with createuser me --username=postgres, but I get the following error:
createuser: error: could not connect to database template1: FATAL: Peer authentication failed for user "postgres"
How do I solve these problems to use PostgreSQL locally on my computer without these problems?
PD: I have reinstalled postgres and now I'm getting a different error while doing psql:
psql: error: could not connect to server: No such file or directory
Is the server running locally and accepting
connections on Unix domain socket "/var/run/postgresql/.s.PGSQL.5432"?
I'm not sure why I had a bad installation, but I have completely uninstalled postgres following this post:
https://kb.objectrocket.com/postgresql/how-to-completely-uninstall-postgresql-757
after that I have restarted my computer and installed posgres again following the proper instructions in:
https://www.postgresql.org/download/linux/ubuntu/
and now it looks like it works without problems
Peer authentication means (there are advanced possibilities, but those are not going to be used by default, while the simple method is the default for apt-installed PostgreSQL) that you have to be the OS user 'postgres' to connect as the database user 'postgres'. So you would do:
sudo -u postgres createuser me
You don't need to specify --username=postgres, since that is the default behavior anyway once you use sudo -u postgres
Alternatively, you could change your pg_hba.conf to use a different authentication method other than peer, if you want to.
You need to provide username in the psql command using -U option.
psql -U postgres
Postgresql comes with a predefined superuser role called postgres. If you want to create more roles, you first have to connect as this initial role.
first check user postgres exists:
$ id postgres
Then:
$ su - postgres
Password:
$ psql
psql (15.1 (Debian 15.1-1.pgdg110+1))
Type "help" for help.
If, Password for user postgres is no known then change it:
$ su - postgres
Password:
su: Authentication failure
$ sudo passwd postgres
New password:
Retype new password:
passwd: password updated successfully
Finally again:
$ su - postgres
Password:
$ psql
psql (15.1 (Debian 15.1-1.pgdg110+1))
Type "help" for help.
I'm trying a tutorial for django that it uses postgresql but I have some issues in setting up the DB. I did change postgres password using sudo passwd postgres and I can login to postgres account using su postgres or sudo su - postgres but after that I can't access the postgres prompt with pqsl. It gives me the following error:
psql: FATAL: password authentication failed for user "postgres"
I've changed the pg_hba.conf file too (from peer to md5) but it didn't change anything.
I've never worked with postgresql and this is my first time using it so if you need any other information please ask me.
sudo passwd postgres is for the system user postgres which is why you can su to system user postgres shell. When you are doing psql -U postgres you are logging in as database user postgres. That is a different account. It is convention that the system user the Postgres server runs as is generally called postgres. Also by convention the Postgres server database 'root/superuser' is the name of the user that the server runs as, so again generally postgres. If you want to log in as postgres user to server using password you will need to create a password for the database user postgres. To do that I would see if in pg_hba.conf the local (not localhost) line is set to trust. If not set it to that and and do:
psql -U postgres -d postgres
Do not specify a -h. This will connect you via a local socket. Then you can :
https://www.postgresql.org/docs/12/sql-alteruser.html
ALTER USER postgres WITH PASSWORD 'your_password'
This will create a password for postgres user.
FYI, you don't have to log into system user postgres account to work as postgres user in database. All you have to do is specify -U postgres to any of the Postgres client programs, psql, pg_dump, etc. This also means you can work as postgres database user on remote servers.
My OS is Fedora 26
I have installed Postgresql and Phoenix.
Postgres has a superuser "postgres" with password "postgres". This is confirmed by running \du in psql.
When I run $ mix ecto.create, I get
** (Mix) The database for Hello.Repo couldn't be created: FATAL 28000 (invalid_authorization_specification): Ident authentication failed for user "postgres"
I suspect it may be a permissions issue. To log into psql requires
$ sudo -u postgres psql postgres
Whereas Phoenix when attempting to use postgres may not have sudo privilages.
$ psql --version
psql (PostgreSQL) 9.6.8
Any thoughts appreciated.
By default the authentication for the postgres database user connecting to the DB locally is to verify that the operating system user is also postgres. This is what the error message refers to as Ident authentication and is why connection after doing sudo -u postgres works.
To connect as the postgres user using another means of authentication you need to edit the pg_hba.conf file. (HBA stands for host based authentication).
The line that allows this will look like this:
local all postgres peer
Add a line that looks like this (without removing the other line!):
local all postgres md5
And you should be able to connect using the password for postgres as well.
If I remember correctly you will need to restart the DB for this to take effect.
I'm setting up my PostgreSQL 9.1 in windows.
I can't do anything with PostgreSQL: can't createdb, can't createuser; all operations return the error message
Fatal: role root does not exist
root is my account name, which I created while installing Postgresql
But I am able to connect using:
username : postgres
How can I connect to postgres using role root?
There is a solution mentioned for linux platforms using su command here but not able to figure out solution for windows7
Thanks in Advance
If you want to login to Postgres using the username root you need to first create such a user.
You first need to login as the Postgres super user. This is typically postgres (and is specified during installation):
psql -U postgres <user-name>
Then you can create roles and databases:
psql (9.4.0)
Type "help" for help.
postgres=# create user root with password 'verysecret';
CREATE ROLE
postgres=# \q
c:\
c:\>psql -U root postgres
psql (9.4.0)
Type "help" for help.
postgres=>
Logged in as the superuser you can also grant the root user the necessary privileges.
All parameters for psql are documented in the manual.
Creating users and databases is also documented in the manual:
connecting to the database
create user
create database
In some cases, when you install postgres the initial DB is not created.
You need to execute initdb.
Same issue appeared while restoring DB/table on postgres docker container .
. When you connect to Postgres DB(psql shell) from inside the docker container, the default user would be a "root" (unless you specify psql -U "some-user-name")
[Manjunath-MacBook-Air:$ sudo docker exec -it a2ff6075344e bash
bash-5.0# psql -U postgres postgres < testdb_pg_dump
So, the issue gets resolved, by logging to psql shell with appropriate username
Here , -U postgres specifies that user connecting to DB is "postgres"
Im new to Postgres and to Heroku. I am trying to pull the database from Heroku but I'm missing something simple. I did:
heroku pg:pull HEROKU_POSTGRESQL_IVORY_URL localdb
And I got the error:
createdb: database creation failed: ERROR: permission denied to create database
Then I tried the same with "sudo". and I got:
createdb: could not connect to database template1: FATAL: role "root" does not exist
So, it must be I'm missing some simple commands I can't find. Im on Linux, I have Postgres installed and working.
createdb is a wrapper around the SQL statement CREATE DATABASE and as such it needs to connect to the database.
By default all Postgres commandline tools try to connect to the database using the current operating system user. As the error message indicates there is not user named root in the database. So you need to pass the name of the Postgres superuser in order for createdb to be able to connect. This user is usually named postgres.
Another option is to switch the Linux user to to postgres if such a Linux user exists.
I don't know Heroku and I don't know how you started createdb, but the parameter to pass a username is -U (for all Postgres command line programs). So you'd need
createdb -U postgres name_of_new_database
Try to use:
sudo su - postgres
Then createdb using:
createdb name_of_db;
When it comes to heroku pg:pull specifically, you can specify the PostgreSQL user and password by specifying the PGUSER and PGPASSWORD environment variables specifically:
PGUSER=postgres PGPASSWORD=password heroku pg:pull HEROKU_POSTGRESQL_MAGENTA mylocaldb --app sushi
If you want to specify the host, for example 127.0.0.1, this is how:
heroku pg:pull HEROKU_POSTGRESQL_MAGENTA postgres://127.0.0.1/mylocaldb --app sushi
See documentation for heroku pg:pull
In some cases you need to execute createdb as the postgres user.
Run createdb (in-line) as postgres user:
sudo -u postgres createdb name_of_database
The command suggested by Ezrqn Kemboi, sudo su - postgres, switches you to the user postgres at which point you would need to exit out of that user to return to whomever you were before hand. This isn't great if you're running this in a script or some form of automation.
The command I suggested will not "switch" to the user and instead will run the command "in-place". My suggestion is more suitable for running in scripts.
Pick whichever you feel is better for your use case.