Just sharing what I have learned about postgres recently. Here is a part of basic commands you may need. Enjoy it!
Before try the following commands, please ensure you are followed the introductions on github: https://github.com/thoughtworks/vagrant-postgresql.
1. boot up a database by virtualBox and vagrant
script/database up
2. login the postgres
psql -h hostname -U username
psql -h localhost -U postgres
Note: password: it depends. Maybe "postgres" or "password" or "secret".
3. list all the databases
\l or \list
4. list all the roles
\du
5. for help
"\h" or "\?" or "help"
it depends on the context.
6. create a new database
create database databasename
create database mydb;
list all the databases, and you can find the database just created.
7. connect to the database
\c databasename
\c mydb
or \connect mydb
8. create a table
create table users (user_id bigserial primary key, user_name varchar(20) not null );
Note: auto_increment is a MySQL feature. Postgres uses serial columns for the same purpose.
9. list tables in connected database
\dt
10. list the schema of a table
\d tablename
\d users
11. get current database name
select current_database();
……
Hopefully these commands will help you getting started with postgres command line quickly. For more information, please feel free to discuss with me or turn to these website:
http://www.postgresql.org/docs/9.1/static/app-psql.html,
http://www.commandprompt.com/ppbook/c4890