def create_book(self, name, price, author):
"""
Validates name & price & author type
Validates Book is not exists by name
Creates a new book into the BOOKS's table
:param name: str
:param price: int | float
:param author: Author
:return: Book | None
"""
# Validates name
if not TypeUtils.is_type(name, var_type=str):
print(ErrorMsgUtils.type_error(name, var_type=str))
return
# Validates price
if not TypeUtils.is_type_or(price, var_type1=int, var_type2=float):
print(ErrorMsgUtils.none_of_type(int, float, var=print()))
return
# Validates author
if not TypeUtils.is_type(author, var_type=Author):
print(ErrorMsgUtils.type_error(author, var_type=Author))
return
# Validates existence
book_to_check = self.find_by_name(name)
if book_to_check is not None:
print(ErrorMsgUtils.already_exists(name))
return
# Validates author existence
author_db = AuthorDBDAO(db=self.db)
author_by_id = author_db.find_by_id(author.id)
if author_by_id is None:
print(
ErrorMsgUtils.does_not_exists(table_name='Author',
var=author.id))
return
# SQL & Execution
sql = f"INSERT INTO BOOKS (NAME, PRICE, AUTHOR_ID) VALUES ('{name}', {price}, {author.id})"
try:
self.cursor.execute(sql)
self.db.commit()
except mysql.connector.Error as error:
print(ErrorMsgUtils.display_error(error))
# Return None
return None
else:
print(self.cursor.rowcount, "was inserted.")
print("ID: ", self.cursor.lastrowid)
# Return the Book
return Book(name=name,
price=price,
id=self.cursor.lastrowid,
author_id=author.id)
def price(self, new_price):
# Validates type
if not TypeUtils.is_type_or(new_price, var_type1=int, var_type2=float):
print(ErrorMsgUtils.none_of_type(int, float, var=new_price))
return
# Validates legal value
if new_price <= 0:
print(ErrorMsgUtils.illegal_value(new_price))
return
# Set value
self.__price = new_price
