2.4a

"""
These imports define the key objects
"""

from flask import Flask
from flask_sqlalchemy import SQLAlchemy

"""
These object and definitions are used throughout the Jupyter Notebook.
"""

# Setup of key Flask object (app)
app = Flask(__name__)
# Setup SQLAlchemy object and properties for the database (db)
database = 'sqlite:///sqlite.db'  # path and filename of databaseapp.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = False
app.config['SQLALCHEMY_DATABASE_URI'] = database
app.config['SECRET_KEY'] = 'SECRET_KEY'
db = SQLAlchemy()


# This belongs in place where it runs once per project
db.init_app(app)
""" database dependencies to support sqlite examples """
import datetime
from datetime import datetime
import json

from sqlalchemy.exc import IntegrityError
from werkzeug.security import generate_password_hash, check_password_hash


''' Tutorial: https://www.sqlalchemy.org/library.html#tutorials, try to get into a Python shell and follow along '''
class Phone(db.Model):
    __tablename__ = 'Phones'  # table name is plural, class name is singular

    id = db.Column(db.Integer, primary_key=True)
    _company = db.Column(db.String(255), unique=False, nullable=False) #_name
    _model = db.Column(db.String(255), unique=True, nullable=False) #_uid
    _price = db.Column(db.String(255), unique=False, nullable=False) # _password
    _dob = db.Column(db.Date) #_dob

    def __init__(self, company, model, price, dob=datetime.today()):
        self._company = company    # variables with self prefix become part of the object, 
        self._model = model
        self._price = price
        # self.set_password(password)
        if isinstance(dob, str):  # not a date type     
            dob = date=datetime.today()
        self._dob = dob

    @property
    def company(self):
        return self._company
    
    @company.setter
    def company(self, company):
        self._company = company
    
    @property
    def model(self):
        return self._model
    
    @model.setter
    def model(self, model):
        self._model = model
        
    def is_model(self, model):
        return self._model == model
    
    @property
    def price(self):
        return self._price
    
    @price.setter
    def price(self, price):
        self._price = price
    
    # @property
    # def password(self):
    #     return self._password[0:10] + "..." # because of security only show 1st characters

    # # update password, this is conventional setter
    # def set_password(self, password):
    #     """Create a hashed password."""
    #     self._password = generate_password_hash(password, method='sha256')

    # # check password parameter versus stored/encrypted password
    # def is_password(self, password):
    #     """Check against hashed password."""
    #     result = check_password_hash(self._password, password)
    #     return result
    
    # dob property is returned as string, to avoid unfriendly outcomes
    @property
    def dob(self):
        dob_string = self._dob.strftime('%m-%d-%Y')
        return dob_string
    
    @dob.setter
    def dob(self, dob):
        if isinstance(dob, str):  # not a date type     
            dob = date=datetime.today()
        self._dob = dob
    
    @property
    def age(self):
        today = datetime.today()
        return today.year - self._dob.year - ((today.month, today.day) < (self._dob.month, self._dob.day))
    
    def __str__(self):
        return json.dumps(self.read())

    def create(self):
        try:
            db.session.add(self)  # add prepares to persist person object to Users table
            db.session.commit()  # SqlAlchemy "unit of work pattern" requires a manual commit
            return self
        except IntegrityError:
            db.session.remove()
            return None

    def read(self):
        return {
            "id": self.id,
            "company": self.company,
            "model": self.model,
            "price": self.price,
            "dob": self.dob,
            "age": self.age,
        }

    def update(self, company="", model="", price=""):
        """only updates values with length"""
        if len(company) > 0:
            self.company = company
        if len(model) > 0:
            self.model = model
        if len(price) > 0:
            self.price = price
        db.session.commit()
        db.session.add(self)
        return self

    def delete(self):
        db.session.delete(self)
        db.session.commit()
        return None
"""Database Creation and Testing """


# Builds working data for testing
def initPhones():
    with app.app_context():
        """Create database and tables"""
        db.create_all()
        """Tester data for table"""
        p1 = Phone(company='Apple', model='iPhone 14', price='799')
        p2 = Phone(company='Apple', model='iPhone 14 Pro', price='999')
        p3 = Phone(company='Samsung', model='Galaxy S23', price='799')
        p4 = Phone(company='LG', model='Wing', price='999')
        p5 = Phone(company='Motorola', model='Razr', price='1399')
        p6 = Phone(company='Google', model='Pixel 7', price='599')

        phones = [p1, p2, p3, p4, p5, p6]

        """Builds sample user/note(s) data"""
        for phone in phones:
            try:
                '''add user to table'''
                object = phone.create()
                print(f"Created new uid {object.model}")
            except:  # error raised if object nit created
                '''fails with bad or duplicate data'''
                print(f"Records exist uid {phone.model}, or error.")
                
initPhones()
Records exist uid iPhone 14, or error.
Records exist uid iPhone 14 Pro, or error.
Records exist uid Galaxy S23, or error.
Records exist uid Wing, or error.
Records exist uid Razr, or error.
Records exist uid Pixel 7, or error.
def find_by_model(model):
    with app.app_context():
        phone = Phone.query.filter_by(_model=model).first()
    return phone # returns user object

# # Check credentials by finding user and verify password
# def check_credentials(model, price):
#     # query email and return user record
#     phone = find_by_model(company)
#     if phone == None:
#         return False
#     if (phone.is_password(price)):
#         return True
#     return False
        
# check_credentials("indi", "123qwerty")
def create():
    # optimize user time to see if uid exists
    model = input("Enter your model:")
    phone = find_by_model(model)
    try:
        print("Found\n", phone.read())
        return
    except:
        pass # keep going
    
    # request value that ensure creating valid object
    company = input("Enter the company:")
    price = input("Enter the price")
    
    # Initialize User object before date
    phone = Phone(company=company, 
                model=model, 
                price=price,
                )
    
    # create user.dob, fail with today as dob
    # dob = input("Enter your date of birth 'YYYY-MM-DD'")
    # try:
    #     user.dob = datetime.strptime(dob, '%Y-%m-%d').date()
    # except ValueError:
    #     user.dob = datetime.today()
    #     print(f"Invalid date {dob} require YYYY-mm-dd, date defaulted to {user.dbo}")
           
    # write object to database
    with app.app_context():
        try:
            object = phone.create()
            print("Created\n", object.read())
        except:  # error raised if object not created
            print("Unknown error uid {uid}")
        
create()
Created
 {'id': 19, 'company': '', 'model': '', 'price': '', 'dob': '03-24-2023', 'age': 0}
# SQLAlchemy extracts all users from database, turns each user into JSON
def read():
    with app.app_context():
        table = Phone.query.all()
    json_ready = [phone.read() for phone in table] # each user adds user.read() to list
    return json_ready

# read()
def delete_by_company(): # makes a new function called delete_by_uid
    model = input("Enter uid of user to be deleted.") # prompts the user to enter the uid
    user = find_by_model(model)  # using previous function to locate user by inputted id
    with app.app_context():
        try:
            object = user.delete() 
            print(f"User with uid --{model}-- has been deleted. ")
            db = read()
            print(db)
        except:  # error raised if object not found
           (f"No user with uid {model} was found.")
        
delete_by_company()
User with uid ---- has been deleted. 

2.4b

import sqlite3

database = 'instance/sqlite.db' # this is location of database

def schema():
    
    # Connect to the database file
    conn = sqlite3.connect(database)

    # Create a cursor object to execute SQL queries
    cursor = conn.cursor()
    
    # Fetch results of Schema
    results = cursor.execute("PRAGMA table_info('phones')").fetchall()

    # Print the results
    for row in results:
        print(row)

    # Close the database connection
    conn.close()
    
schema()
(0, 'id', 'INTEGER', 1, None, 1)
(1, '_company', 'VARCHAR(255)', 1, None, 0)
(2, '_model', 'VARCHAR(255)', 1, None, 0)
(3, '_price', 'VARCHAR(255)', 1, None, 0)
(4, '_dob', 'DATE', 0, None, 0)
import sqlite3

def read():
    # Connect to the database file
    conn = sqlite3.connect(database)

    # Create a cursor object to execute SQL queries
    cursor = conn.cursor()
    
    # Execute a SELECT statement to retrieve data from a table
    results = cursor.execute('SELECT * FROM phones').fetchall()

    # Print the results
    if len(results) == 0:
        print("Table is empty")
    else:
        for row in results:
            print(row)

    # Close the cursor and connection objects
    cursor.close()
    conn.close()
    
read()
(1, 'Apple', 'iPhone 14', '799', '2023-03-20')
(2, 'Apple', 'iPhone 14 Pro', '999', '2023-03-20')
(3, 'Samsung', 'Galaxy S23', '799', '2023-03-20')
(4, 'LG', 'Wing', '999', '2023-03-20')
(5, 'Motorola', 'Razr', '1399', '2023-03-20')
(6, 'Google', 'Pixel 7', '599', '2023-03-20')
(7, 'Google', 'Pixel 7 Pro', '899', '2023-03-20')
(8, 'Samsung', 'ZFold 4', '1999', '2023-03-20')
(9, 'Samsung', 'ZFlip 4', '999', '2023-03-20')
(10, 'Apple', 'iPhone 14 Plus', '899', '2023-03-20')
(11, 'Samsung', 'Galaxy S23 Plus', '999', '2023-03-20')
(12, 'Apple', 'iPhone 14 Pro Max', '1099', '2023-03-20')
(13, 'Samsung', 'Galaxy S23 Ultra', '1199', '2023-03-20')
(14, 'Apple', 'iPhone X', '999', None)
(15, 'Google', 'Pixel 6', '599', None)
(16, 'Google', 'Pixel 6 Pro', '899', None)
(17, 'Apple', 'iPhone XR', '749', '2023-03-22')
(18, 'Samsung', 'Galaxy S22', '799', None)
import sqlite3

def create():
    company = input("Enter the company:")
    model = input("Enter the phone model:")
    price = input("Enter the price")
    # dob = input("Enter your date of birth 'YYYY-MM-DD'")
    
    # Connect to the database file
    conn = sqlite3.connect(database)

    # Create a cursor object to execute SQL commands
    cursor = conn.cursor()

    try:
        # Execute an SQL command to insert data into a table
        cursor.execute("INSERT INTO phones (_company, _model, _price) VALUES (?, ?, ?)", (company, model, price))
        
        # Commit the changes to the database
        conn.commit()
        print(f"A new smartphone record {model} has been created")
                
    except sqlite3.Error as error:
        print("Error while executing the INSERT:", error)


    # Close the cursor and connection objects
    cursor.close()
    conn.close()
    
create()
A new smartphone record  has been created
import sqlite3

def update():
    model = input("Enter smartphone model to update")
    price = input("Enter updated price")
    # if len(password) < 2:
    #     message = "hacked"
    #     password = 'gothackednewpassword123'
    # else:
    #     message = "successfully updated"

    # Connect to the database file
    conn = sqlite3.connect(database)

    # Create a cursor object to execute SQL commands
    cursor = conn.cursor()

    try:
        # Execute an SQL command to update data in a table
        cursor.execute("UPDATE phones SET _price = ? WHERE _model = ?", (price, model))
        if cursor.rowcount == 0:
            # The uid was not found in the table
            print(f"No smartphone model called {model} was found in the table")
        else:
            print(f"The row with {model} has been successfully updated with a price of {price}")
            conn.commit()
    except sqlite3.Error as error:
        print("Error while executing the UPDATE:", error)
        
    
    # Close the cursor and connection objects
    cursor.close()
    conn.close()
    
update()
The row with  has been successfully updated with a price of 
import sqlite3

def delete():
    model = input("Enter a smartphone model to delete")

    # Connect to the database file
    conn = sqlite3.connect(database)

    # Create a cursor object to execute SQL commands
    cursor = conn.cursor()
    
    try:
        cursor.execute("DELETE FROM phones WHERE _model = ?", (model,))
        if cursor.rowcount == 0:
            # The uid was not found in the table
            print(f"No smartphone called {model} was found in the table")
        else:
            # The uid was found in the table and the row was deleted
            print(f"The row with {model} was successfully deleted")
        conn.commit()
    except sqlite3.Error as error:
        print("Error while executing the DELETE:", error)
        
    # Close the cursor and connection objects
    cursor.close()
    conn.close()
    
delete()
The row with  was successfully deleted
def menu():
    operation = input("Enter: (C)reate (R)ead (U)pdate or (D)elete or (S)chema")
    if operation.lower() == 'c':
        create()
    elif operation.lower() == 'r':
        read()
    elif operation.lower() == 'u':
        update()
    elif operation.lower() == 'd':
        delete()
    elif operation.lower() == 's':
        schema()
    elif len(operation)==0: # Escape Key
        return
    else:
        print("Please enter c, r, u, d, or s") 
    menu() # recursion, repeat menu
        
try:
    menu() # start menu
except:
    print("Perform Jupyter 'Run All' prior to starting menu")
(1, 'Apple', 'iPhone 14', '799', '2023-03-20')
(2, 'Apple', 'iPhone 14 Pro', '999', '2023-03-20')
(3, 'Samsung', 'Galaxy S23', '799', '2023-03-20')
(4, 'LG', 'Wing', '999', '2023-03-20')
(5, 'Motorola', 'Razr', '1399', '2023-03-20')
(6, 'Google', 'Pixel 7', '599', '2023-03-20')
(7, 'Google', 'Pixel 7 Pro', '899', '2023-03-20')
(8, 'Samsung', 'ZFold 4', '1999', '2023-03-20')
(9, 'Samsung', 'ZFlip 4', '999', '2023-03-20')
(10, 'Apple', 'iPhone 14 Plus', '899', '2023-03-20')
(11, 'Samsung', 'Galaxy S23 Plus', '999', '2023-03-20')
(12, 'Apple', 'iPhone 14 Pro Max', '1099', '2023-03-20')
(13, 'Samsung', 'Galaxy S23 Ultra', '1199', '2023-03-20')
(14, 'Apple', 'iPhone X', '999', None)
(15, 'Google', 'Pixel 6', '599', None)
(16, 'Google', 'Pixel 6 Pro', '899', None)
(17, 'Apple', 'iPhone XR', '749', '2023-03-22')
(18, 'Samsung', 'Galaxy S22', '799', None)

Extra

'''reference https://www.sqlitetutorial.net/sqlite-python/sqlite-python-select/'''
'''reference https://stackoverflow.com/questions/65401038/python-sqlite3-print-specific-data-only-from-row'''
'''reference https://www.sqlitetutorial.net/sqlite-select/'''
'''reference https://www.quackit.com/sqlite/tutorial/select_data.cfm'''
'''reference https://pynative.com/python-sqlite-select-from-table/'''

# !CODE SEGMENT 1

# def find():
#     findCompany = input("Enter the Name of the Company You Want to Find")
#     if findCompany.lower() == 'Apple':
#         print()
#         AppleResults = cursor.execute("PRAGMA table_info('phones')").fetch(_company)

# !CODE SEGMENT 2

# import sqlite3


# database = 'instance/sqlite.db' # this is location of database

#     # Connect to the database file
# def GetData():
#     conn= sqlite3.connect(database)
#     cursor = conn.cursor()
#     query = ("""SELECT _company FROM phones WHERE _company = 'Apple'""")
#     cursor.execute(query)
#     data = cursor.fetchmany()
#     print(data)
# GetData()

# import sqlite3
# from sqlite3 import Error

# !CODE SEGMENT 3

# def create_connection(db_file):
#     """ create a database connection to a SQLite database """
#     conn = None
#     try:
#         conn = sqlite3.connect(db_file)
#         print(sqlite3.version)
#     except Error as e:
#         print(e)
#     finally:
#         if conn:
#             conn.close()

# if __name__ == '__main__':
#     create_connection(r"///sqlite.db")

def find_by_company(self, company):
    with app.app_context():
        company = input("Input a company")
        phone = Phone.query.filter_by(_company=company).first()
    return phone # returns user object
Phone.read()
---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
/home/edwin/vscode/fastpage1/_notebooks/2023-03-18-DatabaseTrial.ipynb Cell 18 in <cell line: 57>()
     <a href='vscode-notebook-cell://wsl%2Bubuntu/home/edwin/vscode/fastpage1/_notebooks/2023-03-18-DatabaseTrial.ipynb#X23sdnNjb2RlLXJlbW90ZQ%3D%3D?line=54'>55</a>         phone = Phone.query.filter_by(_company=company).first()
     <a href='vscode-notebook-cell://wsl%2Bubuntu/home/edwin/vscode/fastpage1/_notebooks/2023-03-18-DatabaseTrial.ipynb#X23sdnNjb2RlLXJlbW90ZQ%3D%3D?line=55'>56</a>     return phone # returns user object
---> <a href='vscode-notebook-cell://wsl%2Bubuntu/home/edwin/vscode/fastpage1/_notebooks/2023-03-18-DatabaseTrial.ipynb#X23sdnNjb2RlLXJlbW90ZQ%3D%3D?line=56'>57</a> Phone.read()

TypeError: read() missing 1 required positional argument: 'self'

SQLiteplan