# PostgreSQL

# Getting Started

PostgreSQL is an actively developed and mature open source database. Using the psycopg2 module, we can execute queries on the database.

# Installation using pip

pip install psycopg2

# Basic usage

Lets assume we have a table my_table in the database my_database defined as follows.

id first_name last_name
1 John Doe

We can use the psycopg2 module to run queries on the database in the following fashion.

import psycopg2

# Establish a connection to the existing database 'my_database' using
# the user 'my_user' with password 'my_password'
con = psycopg2.connect("host=localhost dbname=my_database user=my_user password=my_password")

# Create a cursor
cur = con.cursor()

# Insert a record into 'my_table'
cur.execute("INSERT INTO my_table(id, first_name, last_name) VALUES (2, 'Jane', 'Doe');")

# Commit the current transaction

# Retrieve all records from 'my_table'
cur.execute("SELECT * FROM my_table;")
results = cur.fetchall()

# Close the database connection

# Print the results

# OUTPUT: [(1, 'John', 'Doe'), (2, 'Jane', 'Doe')]