10ninox/_posts/2014-and-prior/2013-10-26-postgres-101.md

layout	status	published	title	author	date	categories	tags
post	publish	true	PostgreSQL 101	[{display_name sipp11}]	2013-10-26	[database]	postgresql 101

I found that PostgreSQL works differently to MySQL. PostgreSQL will accept command from both command shell ($) and PostgreSQL shell (postgres=#). When you create database, drop database, you can do from command shell:

$ createdb <database-name> -E UTF8
$ dropdb <database-name>

while charset support listed here. or you can create database inside postgres shell.

$ psql
postgres=# create database <database-name>
postgres=# drop database <database-name>

To do some basic query, it's pretty like MySQL. However, it's vastly different when it comes to list/describe

postgres=# \l  # show databases
postgres=# \connect <database-name>  # use database
<database-name>=# \d  # show tables
<database-name>=# \d <table-name>  # show columns
<database-name>=# \d+ <table-name>  # describe table

Configure for remote connection

Server side

Edit /etc/postgres/x.x/main/postgresql.conf

listen_addresses = '*'

Add line to /etc/postgres/x.x/main/pg_hba.conf

host  all  all  0.0.0.0/0  md5

or you could do things like 192.168.1.1/24 if you want to limit to your subnet.

Creating remote user isn't anything different from what local user is:

$ psql template1
template1=# create user <user-name> with password '<your-password>';
template1=# \connect <database-name>;
<database-name>=> GRANT USAGE ON SCHEMA public to <user-name>;
<database-name>=> GRANT SELECT ON ALL TABLES IN SCHEMA public TO <user-name>;
<database-name>=> GRANT UPDATE ON ALL TABLES IN SCHEMA public TO <user-name>;
<database-name>=> GRANT ALL ON ALL TABLES IN SCHEMA public TO <user-name>;
<database-name>=> ALTER DEFAULT PRIVILEGES IN SCHEMA public GRANT SELECT ON TABLES TO <user-name>;
<database-name>=> GRANT USAGE, SELECT ON SEQUENCE <table_name>_id_seq TO <user-name>;
<database-name>=> GRANT USAGE, SELECT ON ALL SEQUENCES IN SCHEMA <schema_name> TO <user-name>;
<database-name>=> \q

Client side

Pretty much like MySQL

$ psql -h <postgres-server> -d <database-name> -U <user-name>

If you don't have postgresql client yet

# apt-get install postgresql-client-x.x

while x.x means version, e.g. postgresql-client-9.1