class Stock(object):
def __init__(self):
self.db = Database()
def increment_stock(self, book_ISBN, increment_amount):
# Increment the stock in the stock table by the increment_amount
# Check that the number the user entered > 0
if (increment_amount < 0):
print("Please put in a value that is greater than 0")
exit()
query = "Update STOCK_LEVEL set AMOUNT = AMOUNT + %d where BOOK_ID = '%s'" %(increment_amount, book_ISBN)
try:
self.db._dbInsert(query)
except Exception as e:
print(e)
def decrement_stock(self, book_ISBN, decrement_amount):
# Decrement the stock in the stock table by the decrement_amoumt
# Check that the number the user entered > 0
if (decrement_amount < 0):
print("Please put in a value that is greater than 0")
exit()
query = "Update STOCK_LEVEL set AMOUNT = AMOUNT - %d where BOOK_ID = '%s'" %(decrement_amount, book_ISBN)
try:
self.db._dbInsert(query)
except Exception as e:
print(e)
class System(object):
def __init__(self):
self.db = Database()
def add_book(self, book_name, book_ISBN, publication_date, price,
author_firstname, author_lastname):
# Add the book to the database
try:
query1 = "Insert into BOOK values ('%s', '%s', '%s', %11.2f)" % (
book_ISBN, book_name, publication_date, price)
query2 = (
"Insert into AUTHOR (GIVEN_NAME, LAST_NAME, BOOK_ID) values ('%s', '%s', '%s')"
% (author_firstname, author_lastname, book_ISBN))
self.db._dbInsert(query1)
self.db._dbInsert(query2)
except Exception as e:
print(e)
def delete_book(self, book_ISBN):
# Remove the book from the database
query = "Delete from BOOK where ISBN = '%s'" % (book_ISBN)
try:
self.db._dbInsert(query)
except Exception as e:
print(e)
class Tag(object):
# Each book is associated with a one word tag
def __init__(self):
self.db = Database()
def add_tag(self, book_ISBN, tag):
# Adds tag to the book
if not (re.match("\A[\w-]+\Z", tag)):
print("Tag can only be a single word")
exit()
query = "Insert into BOOK_TAG (BOOK_ID, TAG) values ('%s', '%s')" % (
book_ISBN, tag)
try:
self.db._dbInsert(query)
except Exception as e:
print(e)
def remove_tag(self, book_ISBN):
# Removes the tag from the book
query = "Delete from BOOK_TAG where BOOK_ID = '%s'" % (book_ISBN)
try:
self.db._dbInsert(query)
except Exception as e:
print(e)
def change_tag(self, book_ISBN, tag):
# Changes the associated tag
query = "Update BOOK_TAG set TAG = '%s' where BOOK_ID = '%s'" % (
tag, book_ISBN)
try:
self.db._dbInsert(query)
except Exception as e:
print(e)