🌟 Python + MySQL Connectivity

Which of the following is the correct method to prevent SQL injection when inserting user input into a MySQL database using PyMySQL?

• Use string concatenation for query formation

• Use %s placeholders in the query and pass values as a tuple

• Use f-string formatting in SQL queries

• Use raw input directly in the SQL query

In a Python program using PyMySQL, what happens if you attempt to insert a record into a table where a NOT NULL column is left empty and no default value is set?

• The record is inserted with NULL in that column

• A ProgrammingError is raised by PyMySQL

• A DataError is raised by the MySQL server

• An IntegrityError is raised by PyMySQL

Consider a table orders(order_id INT PRIMARY KEY, customer_id INT, order_date DATE) and customers(customer_id INT PRIMARY KEY, name VARCHAR(50)). Which query retrieves all orders along with customer names, ensuring that orders without a matching customer are also shown?

• SELECT * FROM orders JOIN customers USING(customer_id)

• SELECT * FROM orders INNER JOIN customers ON orders.customer_id = customers.customer_id

• SELECT * FROM orders LEFT JOIN customers ON orders.customer_id = customers.customer_id

• SELECT * FROM orders RIGHT JOIN customers ON orders.customer_id = customers.customer_id

Given a PyMySQL connection object conn, how do you ensure that changes made via cursor operations are permanently saved in the database?

• Use conn.save()

• Call conn.commit()

• Call conn.flush()

• Call cursor.commit()

Which of the following is NOT a valid reason for a MySQLdb._exceptions.OperationalError: (2006, "MySQL server has gone away") error?

• Query execution timeout

• Server closed the connection due to inactivity

• Data size in a single packet exceeds max_allowed_packet

• Primary key constraint violation in INSERT query

In a PyMySQL program, you attempt to execute the following query: cursor.execute("SELECT * FROM flights WHERE destination = %s", "London"). What is the issue in this statement?

• The placeholder %s must be replaced with the actual value before execution

• The value “London” must be passed as a tuple

• The query will work without any issue

• The query requires a dictionary instead of a tuple for parameter passing

Which of the following tasks would typically require the use of the tabulate module in a PyMySQL application?

• Validating data types in a MySQL table

• Displaying query results in a formatted table view in the console

• Handling SQL exceptions in Python

• Automating database backups

Which of the following options best describes a multi-table query in Python using PyMySQL for retrieving data from two tables based on a condition?

• Write a Python function for each table and merge the results manually

• Use multiple SELECT queries and store results in separate lists

• Write a SQL JOIN query and execute it with cursor.execute()

• It’s not possible to query multiple tables in a single SQL query with PyMySQL

Which of the following correctly handles an exception when attempting to execute an SQL query that could fail due to a unique constraint violation in PyMySQL? try: cursor.execute("INSERT INTO students (id, name) VALUES (%s, %s)", (1, 'John')) conn.commit() except __________ as e: print("Error:", e)

• mysql.connector.Error

• PyMySQL.Error

• pymysql.err.IntegrityError

• Exception

Given the following table definition: CREATE TABLE employee (emp_id INT PRIMARY KEY, name VARCHAR(50), age INT, department VARCHAR(50) DEFAULT 'HR'); What will be the value of department for a record inserted using PyMySQL as below: cursor.execute("INSERT INTO employee (emp_id, name, age) VALUES (%s, %s, %s)", (1, 'Riya', 30)) conn.commit()

• NULL

• ‘HR’

• Raises an error

• Empty string