Ravi Shankar sravi4701

Postgres Cheatsheet

This is a collection of the most common commands I run while administering Postgres databases. The variables shown between the open and closed tags, "<" and ">", should be replaced with a name you choose. Postgres has multiple shortcut functions, starting with a forward slash, "". Any SQL command that is not a shortcut, must end with a semicolon, ";". You can use the keyboard UP and DOWN keys to scroll the history of previous commands you've run.

Setup

installation, Ubuntu

http://www.postgresql.org/download/linux/ubuntu/ https://help.ubuntu.com/community/PostgreSQL

PSQL

Magic words:

psql -U postgres

Some interesting flags (to see all, use -h):

-E: will describe the underlaying queries of the \ commands (cool for learning!)
-l: psql will list all databases and then exit (useful if the user you connect with doesn't has a default database, like at AWS RDS)

	import sys
	from fabric import Connection, task
	from invoke import Responder
	from fabric.config import Config

	PROJECT_NAME = "project_name"
	PROJECT_PATH = "~/{}".format(PROJECT_NAME)
	REPO_URL = "remote_repo_url"

	def get_connection(ctx):

	grades = [5, 6, 7, 8, 9]

	first, *middle, last = grades

	print(first) # 5
	print(last) # 9
	print(middle) # [6, 7, 8]

	# The variable associated with * will always be a list
	# We also can't use two * expression like:

	# comma_separated_variables = sequence

	# given a data in the form of list
	data = ['Ravi', 21, (1996, 12, 5)]

	# extract name, age, dob from data
	name, age, dob = data

	print(name) # Ravi
	print(age) # 21