def find_by_name(self, first_name, last_name):
"""
Validates first_name & last_name are str
Returns Author if exists
:param first_name: str
:param last_name: str
:return: Author | None
"""
# Validates type
if not TypeUtils.all_of_type(first_name, last_name, var_type=str):
print(ErrorMsgUtils.type_error(first_name, last_name,
var_type=str))
return
# Validate legal value
if not first_name:
print(ErrorMsgUtils.illegal_value(first_name))
if not last_name:
print(ErrorMsgUtils.illegal_value(last_name))
sql = f"SELECT * FROM AUTHOR WHERE FIRST_NAME = '{first_name}' AND LAST_NAME = '{last_name}'"
# Execution
try:
self.cursor.execute(sql)
results = self.cursor.fetchone()
if not results:
print(
ErrorMsgUtils.does_not_exists(
table_name='Author', var=f"{first_name}, {last_name}"))
return
# Return results
return Author(id=results[0],
first_name=results[1],
last_name=results[2])
except mysql.connector.Error as error:
print(ErrorMsgUtils.display_error(error))
def create_author(self, first_name, last_name):
"""
Validates type first_name & last_name is str
Validates author does not exists by first & last name
:param first_name: str
:param last_name: str
:return: Author | None
"""
# Validates type
if not TypeUtils.all_of_type(first_name, last_name, var_type=str):
print(ErrorMsgUtils.type_error(first_name, last_name,
var_type=str))
return
# Validate existence
author_to_check = self.find_by_name(first_name, last_name)
if author_to_check is not None:
print(ErrorMsgUtils.already_exists(f"{first_name}-{last_name}"))
return
sql = f"INSERT INTO AUTHOR(FIRST_NAME, LAST_NAME) VALUES ('{first_name}', '{last_name}')"
# Execution
try:
self.cursor.execute(sql)
self.db.commit()
# Error
except mysql.connector.Error as error:
print(ErrorMsgUtils.display_error(error))
else:
print(self.cursor.rowcount, "was inserted.")
print("ID: ", self.cursor.lastrowid)
# Return the Book
return Author(first_name=first_name,
last_name=last_name,
id=self.cursor.lastrowid)