Connect To PostgreSQL Database Server and Execute SQL Statement in Python

by Taha Sıvacı · June 8, 2019

Hello everyone, in today article , I will talk in detail how to connect to the PostgreSQL database and execute sql statement in python.

First add psycopg2 package to the project

2	import psycopg2

If you recieve an error “no module name” , perform the install package as follows.

if you recieve an error Installing packages: error occurred , perform the install package as follows command line

sudo apt-get install postgresql

sudo apt-get install python-psycopg2

sudo apt-get install libpq-dev

For you connection can use a list of keyword arguments:

2 3	connection = psycopg2.connect(host="localhost",database="dbname", user="username", password="password")

2	cursor = connect.cursor()

2	cursor.execute('SELECT *from layername')

2	cur.fetchone()

Display Output :

Insert SQL :

cursor = connection.cursor()

cursor.execute("INSERT INTO a_table (c1, c2, c3) VALUES(%s, %s, %s)", (v1, v2, v3))

cursor.close()

connnection.close()

Update SQL:

cursor = connection.cursor()

cursor.execute("UPDATE table_name SET update_column_name=(%s) WHERE ref_column_id_value = (%s)", ("column_name","value_you_want_to_update",));

connection.commit()

cursor.close()

Delete SQL:

cursor.execute("DELETE FROM parts WHERE part_id = %s", (part_id,))

cursor.close()

connection.close()

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