How to setup a Postgres Server on Ubuntu


Installing on Linux

$ sudo apt-get update

$ sudo apt-get install postgresql postgresql-contrib

Switch over to the postgres account on your server by typing:

$ sudo -i -u postgres

You can now access a Postgres prompt immediately by typing:

$ psql, exit with \q

Creating user

$ sudo -u postgres createuser <username>

Creating Database

$ sudo -u postgres createdb <dbname>

Giving the user a password

$ sudo -u postgres psql

psql=# alter user <username> with encrypted password '<password>';

Granting privileges on database

psql=# grant all privileges on database <dbname> to <username> ;

Access remotely

  1. $ sudo su - postgres
  2. postgres:$ vi /etc/postgresql/9.5/main/postgresql.conf Search after listen_addresses and uncomment that line or add this listen_addresses = '*'
  3. postgres:$ vi /etc/postgresql/9.5/main/pg_hba.conf Append at the end of the file these:
host    all     all     0.0.0.0/0       md5
host    all     all     ::/0            md5
  1. Restart postgres $ sudo service postgresql restart

PS: Make sure that you have postgres version 9.5 $ psql --version . If the file it’s empty try to use autocomplete vi /etc/postgresql/ and then press tab for version autocomplete.

Useful commands

Show all databases \l+

Show all roles \du+

Show all tables \dt

Reset auto increment counter in postgres

Firstly you need to find your sequence identifier for the column that you want to reset the counter. Usually the name it’s the name of the table followed by column name followed by _seq.

Example:

table name: ‘users’ column name: ‘id’

sequence name will be: users_id_seq

First you need to find the current maximum value:

SELECT setval('users_id_seq', max(id)) FROM  accounts;

then you can reset it with one of these commands:

SELECT setval('accounts_id_seq', DESIRED_VALUE);

or

ALTER SEQUENCE accounts_id_seq RESTART WITH DESIRED_VALUE;