class ManageContacts:
"""
This class manages user's contacts to add contact, show contacts, search contact, etc.
In the class constructor, i.e., __init__, a database connection is established.
"""
def __init__(self):
# connect to database
self.db = DatabaseConnection()
self.db_connect = self.db.connect_database()
# create a Cursor() method from established database connection
self.cur = self.db_connect.cursor()
# CRUD operations, i.e., 'C' in CRUD stands for Create, 'R' for Read,
# 'U' for Update, and 'D' for Delete.
def create_contact(self, first_name, last_name, address, phone, email,
notes, username):
try:
query_insert_contact = """
INSERT INTO contacts(first_name, last_name, address,
phone, email, notes, username)
VALUES (?, ?, ?, ?, ?, ?, ?)
"""
params = (first_name, last_name, address, phone, email, notes,
username)
self.cur.execute(query_insert_contact, params)
self.db_connect.commit()
return True
except sqlite3.Error as err:
print('Err: ', err.message)
return False
def read_contacts(self, username):
try:
query_show_contacts = """
SELECT * FROM contacts
WHERE username = ?
"""
params = (username, )
self.cur.execute(query_show_contacts, params)
data = self.cur.fetchall()
print("""
--- List of your contacts stored in AddressBook App ---
""")
for row in list(data): # NOTE The list() function forces print()
# to print all records returned by fetchall().
print(row)
return True
except sqlite3.Error as err:
print('Err: ', err.message)
return False
def update_contact(self, username, first_name, phone):
# NOTE first_name and phone makes unique operation
# TODO complete update_contact() function
pass
def delete_contact(self, username, first_name, last_name):
# TODO In create_contacts() function implement defensive code to not allow user insert
# TODO a new contact with existing first_name and last_name
pass
def search_contact(self, username, first_name_start):
try:
query_search = """
SELECT * FROM contacts
WHERE username = ? AND first_name LIKE ?
"""
first_name_pattern = first_name_start + '%'
params = (username, first_name_pattern)
self.cur.execute(query_search, params)
data = self.cur.fetchall()
if data:
print("""
--- Your search result: ---
""")
for row in list(data):
print(row)
return True
else:
print("No contact found!")
return False
except sqlite3.Error as err:
print('Err: ', err.message)
return False
class ManageUsers:
"""
This class manages users to add user, show users, update and delete user.
In the class constructor, i.e., __init__, a database connection is established.
"""
def __init__(self):
# connect to database
self.db = DatabaseConnection()
self.db_connect = self.db.connect_database()
# create a Cursor() method from established database connection
self.cur = self.db_connect.cursor()
# CRUD operations, i.e., 'C' in CRUD stands for Create, 'R' for Read,
# 'U' for Update, and 'D' for Delete.
def create_user(self, username, first_name, last_name,
password, password_again):
# Validation step: check if username is already taken
check_username = self.validate_username(username)
if check_username:
print("""
WARNING MESSAGE - The username exists. Please try again.
""")
return False
else:
# Validation step: password validation
check_password = self.validate_password(password, password_again)
if check_password:
# Register the user
try:
query_insert_user = """
INSERT INTO users(username, first_name, last_name, password)
VALUES(?, ?, ?, ?)
"""
params = (username, first_name, last_name, password)
self.cur.execute(query_insert_user, params)
self.db_connect.commit()
return True
except sqlite3.Error as err:
print('Err: ', err.message)
return False
else:
print("""
Password mismatch. Please try again!
""")
return False
def read_users(self):
try:
query_show_users = "SELECT * FROM users"
self.cur.execute(query_show_users)
data = self.cur.fetchall()
print("""
--- List of users for AddressBook App ---
""")
for row in list(data): # NOTE The list() function forces print()
# to print all records returned by fetchall().
print(row)
return True
except sqlite3.Error as err:
print('Err: ', err.message)
return False
def update_user(self, username):
pass # TODO complete update_user() function
def delete_user(self, username):
pass # TODO complete delete_user() function
def login(self, username, password):
try:
query_login_credentials = """
SELECT * FROM users
WHERE username = ? AND password = ?
"""
params = (username, password)
self.cur.execute(query_login_credentials, params)
data = self.cur.fetchall() # NOTE sqlite3 returns a tuple, e.g., (1, 'test', 'qwe', 'qwe', 'test')
if data:
# store user credentials as a dictionary
result = {'id': data[0][0],
'username': data[0][1],
'first_name': data[0][2],
'last_name': data[0][3]}
return result
else:
print("""
WARNING MESSAGE - Login failed. Please try again!
""")
return False
except sqlite3.Error as err:
print('Err: ', err.message)
return False
def validate_username(self, username):
try:
query_find_user = "******"
params = (username,)
self.cur.execute(query_find_user, params)
data = self.cur.fetchone()
if data:
return True
else:
return False
except sqlite3.Error as err:
print('Err: ', err.message)
return False
def validate_password(self, password, password_again):
# TODO Method validate_password might be static - read and understand
if password != password_again:
return False
else:
return True
