I'm taking a full WebDev course and got really hard stuck on this matter. I've installed postgreSQL 14.2 for Windows 10 and the instructor said that pgAdmin4 would come together, which it didn't, so then i installed pgAdmin4 individually. I've setted everything up and created a testing database, which is called 'test', and also a table, everything through Windows Powershell command lines, following the course instructions. Now, when i try to access this database through PowerShell command psql 'test' and type the requested password for the OS user i get a Fatal Error, which follows:
PS C:\Users\theu_\desktop> psql 'test'
Password for user theu_:
psql: error: connection to server at "localhost" (::1), port 5432 failed: FATAL: password authentication failed for user "theu_"
I've tried my OS username password and the postgreSQL password, none of them works. What am i missing or did wrong?
Thanks in advance
Try accessing postgres by using psql -U postgres in cmd, postgres being the name of the superuser for postgres itself (if you did a basic install) - while windows is probably trying to access postgres with your windows name.
You should also be able to use SQL Shell to access your database without denoting a user.
I accidentally removed the super user privilege from user: postgres. I don't know how to get another super user. I stopped the postgres service and tried logging in with single-user mode:
/usr/pgsql-10/bin/postgres --single -D /var/lib/pgsql/10/data
I get this error:
"root" execution of the PostgreSQL server is not permitted.
The server must be started under an unprivileged user ID to prevent
possible system security compromise. See the documentation for
more information on how to properly start the server.
In Linux, how can I start Postgres in single-user mode so I can fix the super user privilege?
Edit: I used this link for reference, but I'm getting the error mentioned above.
Accidently removed postgres default superuser privileges - can I get it back?
I combined solutions from these three links:
Accidently removed postgres default superuser privileges - can I get it back?
Restoring the superuser account on the postgres server
“root” execution of the PostgreSQL server is not permitted
After stopping the postgresql service, I ran this command:
sudo -u postgres /usr/pgsql-10/bin/postgres --single -D /var/lib/pgsql/10/data
/usr/pgsql-10/bin/postgres is the location of my postgres binary
/var/lib/pgsql/10/data is the location of my postgresql conf
This allowed me to access single user mode, where I just typed this command:
ALTER USER postgres SUPERUSER;
So if anyone is experiencing the same scenario as me, please give the posted command a try.
just adding this for postgresql 12 (Ubuntu) and possibly up
sudo -su postgres /usr/lib/postgresql/12/bin/postgres --single -D /etc/postgresql/12/main
I'm trying to create db on PostgreSQL on linux machine. And I use following command to create the DB.
createdb mydbname;
This is throwing following error.
createdb: could not connect to database postgres: FATAL: database
"postgres" does not exist
I'm new to PostgreSQL. Can you please guide me to go through this error? Simply I want to create a DB on psql.
It looks like you dropped the postgres database. It's the default used for many admin operations, so you might want to re-create it:
createdb --maintenance-db=template1 -T template0 postgres;
What that's doing is connecting to the built-in DB template1 in order to create the db postgres by making a copy of template0.
Once that's done, your command:
createdb mydbname;
will work as normal.
su - postgres change user to postgres
psql - run psql terminal
postgres# create database somedatabase create database;
postgres#\c somedatabase connecto to database
somedatabase# your are connected to that database as postgres user
su - postgres change user to postgres
createdb
createdb somedatabase
psql somedatabase
The first line changes to the postgres system user. The second line creates a database for the postgres admin user. The third line creates the database you were trying to make. The fourth line connects to it as the postgres user.
I want to create user and database in linux server.
I am able to create user with the following code:
su - postgres
# createuser -S -D -R myUser
but when I tried to create database with code :
# createdb -U myUser -p 5432 myDatabase
I get following error:
createdb: could not connect to database postgres: FATAL: Ident authentication failed for user "myUser"
I am new to linux so I am unable to figure out why I was able to create user but while creating database there is connection error with postgres. And also error for ident
authentication for user.
I am new to linux so I am unable to figure out why I was able to create user but while
creating database there is connection error with postgres. And also error for ident
authentication for user.
ident is an authentication schema that relies on the currently logged in user. If you've su -s to postgres and then try to login as another user, ident will fail (as it's not the currently logged in user). You can solve this issue in two ways, I tend to use the latter.
solution: simply make sure the currently logged in user is the user with which you would like to log in to postgres:
postgres#machine:~$ createuser -S -D -R myUser
postgres#machine:~$ exit
machine:~# su - myUser
myUser#machine:~$ psql myDatabase
better solution: change pg_hba.conf (probably located in /etc/postgresql/8.4/main/ or similar), and make sure you add the "md5" authentication schema to the list of options. Here's my pg_hba.conf on my development box, without comments:
berry#berry-pc:~$ sudo cat /etc/postgresql/8.4/main/pg_hba.conf | grep -v "^#" | grep -v "^$"
local all postgres ident
local all all md5
host all all 127.0.0.1/32 md5
host all all ::1/128 md5
This tells PostgreSQL that postgres can login with ident, and all other users can login using the md5 authentication. That way, you can use the -U switch to the psql binary to denote which user you wish to become, so this actually works:
berry#berry-pc:~$ psql -U myUser myDatabase.
That said, I tend to use the postgres superuser to create databases. I then grant permissions on the newly created database to the newly created user, as such:
postgres#debian:~$ psql template1
template1=# CREATE USER myUser WITH PASSWORD 'myPassword';
CREATE ROLE
template1=# CREATE DATABASE myDatabase;
CREATE DATABASE
template1=# GRANT ALL PRIVILEGES ON DATABASE myDatabase TO myUser;
GRANT
template1=# \q
Hope that helps.
ADDENDUM: Once you've altered the pg_hba.conf, you will have to restart the PostgreSQL server to make sure it reads the configuration again. You can do so by issuing this command:
root#debian:~$ /etc/init.d/postgresql-8.4 restart
The script might be called "postgresql" instead of "postgresql-8.4", depending on OS and method of installation.
I have just installed postgresql and I specified password x during installation.
When I try to do createdb and specify any password I get the message:
createdb: could not connect to database postgres: FATAL: password authentication failed for user
Same for createuser.
How should I start?
Can I add myself as a user to the database?
The other answers were not completely satisfying to me. Here's what worked for postgresql-9.1 on Xubuntu 12.04.1 LTS.
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.
Under Linux PostgresQL is usually configured to allow the root user to login as the postgres superuser postgres from the shell (console or ssh).
$ psql -U postgres
Then you would just create a new database as usual:
CREATE ROLE myuser LOGIN password 'secret';
CREATE DATABASE mydatabase ENCODING 'UTF8' OWNER myuser;
This should work without touching pg_hba.conf. If you want to be able to do this using some GUI tool over the network - then you would need to mess with pg_hba.conf.
There are two methods you can use. Both require creating a user and a database.
Using createuser and createdb,
$ sudo -u postgres createuser --superuser $USER
$ createdb mydatabase
$ psql -d mydatabase
Using the SQL administration commands, and connecting with a password over TCP
$ sudo -u postgres psql postgres
And, then in the psql shell
CREATE ROLE myuser LOGIN PASSWORD 'mypass';
CREATE DATABASE mydatabase WITH OWNER = myuser;
Then you can login,
$ psql -h localhost -d mydatabase -U myuser -p <port>
If you don't know the port, you can always get it by running the following, as the postgres user,
SHOW port;
Or,
$ grep "port =" /etc/postgresql/*/main/postgresql.conf
Sidenote: the postgres user
I suggest NOT modifying the postgres user.
It's normally locked from the OS. No one is supposed to "log in" to the operating system as postgres. You're supposed to have root to get to authenticate as postgres.
It's normally not password protected and delegates to the host operating system. This is a good thing. This normally means in order to log in as postgres which is the PostgreSQL equivalent of SQL Server's SA, you have to have write-access to the underlying data files. And, that means that you could normally wreck havoc anyway.
By keeping this disabled, you remove the risk of a brute force attack through a named super-user. Concealing and obscuring the name of the superuser has advantages.
This is my solution:
su root
su postgres
psql
EDIT: Warning: Please, read the answer posted by Evan Carroll. It seems that this solution is not safe and not recommended.
This worked for me in the standard Ubuntu 14.04 64 bits installation.
I followed the instructions, with small modifications, that I found in http://suite.opengeo.org/4.1/dataadmin/pgGettingStarted/firstconnect.html
Install postgreSQL (if not already in your machine):
sudo apt-get install postgresql
Run psql using the postgres user
sudo –u postgres psql postgres
Set a new password for the postgres user:
\password postgres
Exit psql
\q
Edit /etc/postgresql/9.3/main/pg_hba.conf and change:
#Database administrative login by Unix domain socket
local all postgres peer
To:
#Database administrative login by Unix domain socket
local all postgres md5
Restart postgreSQL:
sudo service postgresql restart
Create a new database
sudo –u postgres createdb mytestdb
Run psql with the postgres user again:
psql –U postgres –W
List the existing databases (your new database should be there now):
\l
In MacOS, I followed the below steps to make it work.
For the first time, after installation, get the username of the system.
$ cd ~
$ pwd
/Users/someuser
$ psql -d postgres -U someuser
Now that you have logged into the system, and you can create the DB.
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
If you're running macOS like I am, you may not have the postgres user.
When trying to run sudo -u postgres psql I was getting the error sudo: unknown user: postgres
Luckily there are executables that postgres provides.
createuser -D /var/postgres/var-10-local --superuser --username=nick
createdb --owner=nick
Then I was able to access psql without issues.
psql
psql (10.2)
Type "help" for help.
nick=#
If you're creating a new postgres instance from scratch, here are the steps I took. I used a non-default port so I could run two instances.
mkdir /var/postgres/var-10-local
pg_ctl init -D /var/postgres/var-10-local
Then I edited /var/postgres/var-10-local/postgresql.conf with my preferred port, 5433.
/Applications/Postgres.app/Contents/Versions/10/bin/postgres -D /Users/nick/Library/Application\ Support/Postgres/var-10-local -p 5433
createuser -D /var/postgres/var-10-local --superuser --username=nick --port=5433
createdb --owner=nick --port=5433
Done!
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`
You probably need to update your pg_hba.conf file. This file controls what users can log in from what IP addresses. I think that the postgres user is pretty locked-down by default.
Just browse up to your installation's directory and execute this file "pg_env.bat", so after go at bin folder and execute pgAdmin.exe. This must work no doubt!