Почему не сохраняются действия программы с базой данных?

import psycopg2

connection = psycopg2.connect(host="localhost", user="postgres", password="password")
cursor = connection.cursor()

if True:
    cursor.execute("""CREATE TABLE products (id serial PRIMARY KEY,name varchar (40) NOT NULL, description varchar (255) NOT NULL, attachments varchar (255) NOT NULL, selled serial, author_id serial NOT NULL, customer serial, checher serial NOT NULL);""")

commands = [
    "INSERT INTO products (name, description, attachments, selled, author_id, customer,  checher) VALUES ('Its Product', 'Its description', 'Its attachments', 0, 1, 0, 0)",
    "SELECT * FROM products",
    ]
for i in range(3):
    for query in range(len(commands)):
        cursor.execute(commands[query])
        try:
            data = cursor.fetchall()
            print(i+1)
            for _ in data:
                print("   ",_)
        except:
            continue