Install PostgreSQL in Ubuntu 16.04

ReadMe.txt

#Update your apps by below command and install 

$ sudo apt-get update
$ sudo apt-get install postgresql postgresql-contrib

#Connect to PostgreSQL
$ sudo su - postgres
$ psql

#Checking connection with user information
postgres-# \conninfo

#Leave the connection 
postgres-# \q

Now Install a web interface admin for the PostgreSQL database. It is called phpPgAdmin .
Firstly run this command

$ sudo apt-get update

Then 
$ sudo apt-get install phppgadmin

For accessing the interface 
http://localhost/phppgadmin hit on your browser :P 

Now you need to password and username for login purpose :D 

So your default username is postgres now need to add a password for security purpose. let's create a password 

for creating password you need to run below commands step by step

#Connect to PostgreSQL
$ sudo su - postgres
$ psql

Now enter below command
 \password postgres
 you will see like this 
 Enter your new password and enter again your password . Hope you can understand what you need to do now . :P 
 
 and finlly logout from the connection . 
 
 Now you need to edit two files of PostgreSQL . 
 
 One is called phppgadmin.conf . You can find this file on this path 
 
 /etc/apache2/conf-available/phppgadmin.conf 
 
 Now you need to do below task . 
 
 One put a comment on Require local (you can comment the text by using #)
and add this code below the Require local text 

order deny,allow
deny from all
allow from 127.0.0.0/255.0.0.0 ::1/128

Another file is called config.inc.php . You can find this file on etc/phppgadmin/config.inc.php 

Now edit the file and find the below line 

$conf['extra_login_security'] = true;

replace the true to false . then you can access the postgresql server by phppgadmin :D

By the way lastly you should restart the appach server by this command 
$ sudo service apache2 reload

That's all my friends :D

Happy Coding 

Source: 1. https://tecadmin.net/install-postgresql-server-on-ubuntu/#
        2. https://www.howtoforge.com/tutorial/ubuntu-postgresql-installation/