Unable to execute Postgres queries in Python

Question

I'm trying to create a Postgres table using psycopg2 in Python as follows:

import psycopg2
class DbOperations (object):
def __init__(self):
 self.dummy = None
 self.conn = None
 self.cur = None
 self.query = None
 self.db_name = "alarm_log"
 self.table_name = "alarms"
 self.user = "cayman"
 self.password = "admin"
 self.host = "127.0.0.1"
def db_connect(self):
 self.conn = psycopg2.connect(dbname=self.db_name, user=self.user, password=self.password, host=self.host)
 self.cur = self.conn.cursor()
def db_disconnect(self):
 self.conn.close()
def db_create_table(self):
 self.query ="""
 CREATE TABLE COMPANY(
 ID INT PRIMARY KEY NOT NULL,
 NAME TEXT NOT NULL,
 AGE INT NOT NULL,
 ADDRESS CHAR(50),
 SALARY REAL
 );
 """
 print (self.query)
 self.cur.execute(self.query)

Then I construct the object as follows:

db_app = DbOperations()
db_app.db_connect()
db_app.db_create_table()

I am able to manually connect to the database and create the table. However, I'm not able to do so using Python. There are no exceptions or error messages. When I try to list the tables in the database manually, I don't find my newly created table. Any suggestions what could be wrong ?

• Iron Fist: So what went wrong?, Any error message to post that could help solving your case? :)
• Joseph Wahba: Eventually there are no exceptions or error messages. When I try to list the tables in the database manually, I don't find my newly created table
• Maurice Meyer: You should commit after execute :)

Answer 1

Seems, you are missing the commit at the end of db_create_table method:

self.conn.commit()

• Joseph Wahba: Thanks it worked. I was following Python's documentation for psycopg2 but it never mentioned so! weird
• Iron Fist: Can you post the link to it?

Answer 2

Iron Fist's answer is absolutely correct, but if you don't want to have commits all over your code, you can also set it on the connection like this:

def db_connect(self):
 self.conn = psycopg2.connect(dbname=self.db_name, user=self.user, password=self.password, host=self.host)
 self.conn.autocommit = True
 self.cur = self.conn.cursor()