postgres psycopg2 tutorial code example

Example 1: psycopg2 select example

import psycopg2

try:
   connection = psycopg2.connect(user="sysadmin",
                                  password="pynative@#29",
                                  host="127.0.0.1",
                                  port="5432",
                                  database="postgres_db")
   cursor = connection.cursor()
   postgreSQL_select_Query = "select * from mobile"

   cursor.execute(postgreSQL_select_Query)
   print("Selecting rows from mobile table using cursor.fetchall")
   mobile_records = cursor.fetchall() 
   
   print("Print each row and it's columns values")
   for row in mobile_records:
       print("Id = ", row[0], )
       print("Model = ", row[1])
       print("Price  = ", row[2], "\n")

except (Exception, psycopg2.Error) as error :
    print ("Error while fetching data from PostgreSQL", error)

finally:
    #closing database connection.
    if(connection):
        cursor.close()
        connection.close()
        print("PostgreSQL connection is closed")

Example 2: how to connect postgres database to python

import psycopg2
from psycopg2 import Error

try:
    connection = psycopg2.connect(user = "postgres",
                                  password = "pass@#29",
                                  host = "127.0.0.1",
                                  port = "5432",
                                  database = "postgres_db")

    cursor = connection.cursor()
    
    create_table_query = '''CREATE TABLE mobile
          (ID INT PRIMARY KEY     NOT NULL,
          MODEL           TEXT    NOT NULL,
          PRICE         REAL); '''
    
    cursor.execute(create_table_query)
    connection.commit()
    print("Table created successfully in PostgreSQL ")

except (Exception, psycopg2.DatabaseError) as error :
    print ("Error while creating PostgreSQL table", error)
finally:
    #closing database connection.
        if(connection):
            cursor.close()
            connection.close()
            print("PostgreSQL connection is closed")