30+ MCQs on Database Interaction with Python
Welcome to the Python Database Interaction Python Interview Questions! Database interaction is a fundamental aspect of many Python applications, allowing you to store, retrieve, and manipulate data in various database systems. Python provides several libraries such as sqlite3, MySQLdb, psycopg2, and sqlalchemy to interact with databases. These questions will test your understanding of how to connect to databases, execute queries, fetch results, handle transactions, and more using Python. Each question is multiple-choice, with only one correct answer. Take your time to carefully read each question and choose the best option. Let’s explore the world of Python database interaction together!
30+ Python Interview Questions on Database Interaction with Python
Q1. Which of the following modules is commonly used in Python for interacting with databases?
a) sqlalchemy
b) matplotlib
c) requests
d) datetime
Answer: a
Explanation: The sqlalchemy module is commonly used in Python for interacting with databases.
Q2. What is the purpose of the sqlite3 module in Python?
a) To perform mathematical operations
b) To interact with SQLite databases
c) To generate random numbers
d) To handle JSON data
Answer: b
Explanation: The sqlite3 module in Python is used to interact with SQLite databases.
Q3. Which Python library provides an ORM (Object-Relational Mapping) for database interaction?
a) sqlalchemy
b) pandas
c) numpy
d) requests
Answer: a
Explanation: The sqlalchemy library in Python provides an ORM (Object-Relational Mapping) for database interaction.
Q4. What does ORM stand for in the context of database interaction?
a) Object-Relational Model
b) Object-Relational Mapping
c) Object-Record Management
d) Object-Relational Middleware
Answer: b
Explanation: ORM stands for Object-Relational Mapping, which is a technique for converting data between incompatible systems.
Q5. Which of the following is NOT a popular relational database management system (RDBMS)?
a) SQLite
b) MongoDB
c) MySQL
d) PostgreSQL
Answer: b
Explanation: MongoDB is a popular NoSQL database, not a relational database management system.
Q6. Which method is used to establish a connection to a database using sqlite3 in Python?
a) connect()
b) create_connection()
c) open_connection()
d) establish_connection()
Answer: a
Explanation: The connect() method is used to establish a connection to a database using sqlite3 in Python.
Q7. What is the purpose of the cursor() method in Python’s database interaction?
a) To create a new database
b) To execute SQL queries
c) To close the database connection
d) To fetch all records from a table
Answer: b
Explanation: The cursor() method is used to create a cursor object, which is used to execute SQL queries.
Q8. Which method is used to execute an SQL query and fetch all the results in Python’s database interaction?
a) execute_query()
b) fetch_all()
c) execute_fetch_all()
d) fetchall()
Answer: d
Explanation: The fetchall() method is used to execute an SQL query and fetch all the results in Python’s database interaction.
Q9. What is the purpose of the commit() method in Python’s database interaction?
a) To execute a transaction
b) To fetch results from the database
c) To close the database connection
d) To roll back changes
Answer: a
Explanation: The commit() method is used to execute a transaction and save changes to the database.
Q10. Which SQL command is used to retrieve data from a database table?
a) SELECT
b) UPDATE
c) INSERT INTO
d) DELETE FROM
Answer: a
Explanation: The SELECT SQL command is used to retrieve data from a database table.
Q11. What does the fetchone() method do in Python’s database interaction?
a) Fetches all rows from the result set
b) Fetches the next row of a query result set
c) Fetches the first row of a query result set
d) Fetches a specific row based on index
Answer: c
Explanation: The fetchone() method fetches the first row of a query result set in Python’s database interaction.
Q12. Which of the following methods is used to execute parameterized SQL queries in sqlite3?
a) execute_query()
b) execute_params()
c) execute()
d) execute_script()
Answer: c
Explanation: The execute() method is used to execute parameterized SQL queries in sqlite3.
Q13. What does the fetchall() method return in Python’s database interaction?
a) The number of rows affected by the last SQL command
b) A list of tuples representing each row of the result set
c) The first row of the result set
d) The last row of the result set
Answer: b
Explanation: The fetchall() method returns a list of tuples representing each row of the result set.
Q14. Which method is used to close the cursor in Python’s database interaction?
a) close()
b) cursor_close()
c) destroy()
d) cursor_destroy()
Answer: a
Explanation: The close() method is used to close the cursor in Python’s database interaction.
Q15. What is the purpose of the rollback() method in Python’s database interaction?
a) To execute a transaction
b) To fetch results from the database
c) To undo changes made since the last commit()
d) To close the database connection
Answer: c
Explanation: The rollback() method is used to undo changes made since the last commit() in Python’s database interaction.
Q16. Which of the following is NOT a common method to prevent SQL injection in Python’s database interaction?
a) Using parameterized queries
b) Escaping special characters
c) Using raw SQL queries
d) Using an ORM framework
Answer: c
Explanation: Using raw SQL queries directly is a common cause of SQL injection vulnerabilities.
Q17. What does the rowcount attribute of a cursor object represent in Python’s database interaction?
a) The number of rows affected by the last SQL command
b) The total number of rows in a table
c) The number of columns in the result set
d) The index of the current row being fetched
Answer: a
Explanation: The rowcount attribute of a cursor object represents the number of rows affected by the last SQL command.
Q18. Which method is used to execute multiple SQL commands in a single call in sqlite3?
a) execmany()
b) executescript()
c) execute_many()
d) execute_script()
Answer: b
Explanation: The executescript() method is used to execute multiple SQL commands in a single call in sqlite3.
Q19. What is the purpose of the fetchmany() method in Python’s database interaction?
a) To fetch a specific number of rows from the result set
b) To fetch all rows from the result set
c) To fetch the first row of the result set
d) To fetch the last row of the result set
Answer: a
Explanation: The fetchmany() method is used to fetch a specific number of rows from the result set in Python’s database interaction.
Q20. Which of the following is NOT true about transactions in database interaction?
a) A transaction consists of one or more SQL statements
b) Transactions ensure that either all changes are made or none
c) Transactions are not supported in SQLite
d) Transactions can be committed or rolled back
Answer: c
Explanation: Transactions are supported in SQLite, and they ensure that either all changes are made or none, maintaining data integrity.
Q21. What does the lastrowid attribute of a cursor object represent in Python’s database interaction?
a) The ID of the last inserted row
b) The total number of rows in a table
c) The number of columns in the result set
d) The index of the current row being fetched
Answer: a
Explanation: The lastrowid attribute of a cursor object represents the ID of the last inserted row.
Q22. Which method is used to create a new table in a database using sqlite3 in Python?
a) create_table()
b) execute()
c) make_table()
d) table_create()
Answer: b
Explanation: The execute() method is used to execute SQL commands, including creating a new table in sqlite3.
Q23. What is the purpose of the fetchall() method in Python’s database interaction?
a) To fetch all rows from the result set
b) To fetch a specific number of rows
c) To fetch the first row of the result set
d) To fetch the last row of the result set
Answer: a
Explanation: The fetchall() method is used to fetch all rows from the result set in Python’s database interaction.
Q24. Which SQL command is used to update existing records in a database table?
a) UPDATE
b) INSERT INTO
c) SELECT
d) DELETE FROM
Answer: a
Explanation: The UPDATE SQL command is used to update existing records in a database table.
Q25. How do you fetch the next row of a query result set in Python’s database interaction?
a) fetch_next()
b) fetch_next_row()
c) fetchone()
d) fetch_row()
Answer: c
Explanation: The fetchone() method fetches the next row of a query result set in Python’s database interaction.
Q26. Which of the following methods is used to execute a parameterized SQL query in sqlite3?
a) execute()
b) execute_params()
c) execute_query()
d) execute_script()
Answer: a
Explanation: The execute() method in sqlite3 is used to execute a parameterized SQL query.
Q27. What does the rowcount attribute of a cursor object represent in Python’s database interaction?
a) The number of rows affected by the last SQL command
b) The total number of rows in a table
c) The number of columns in the result set
d) The index of the current row being fetched
Answer: a
Explanation: The rowcount attribute of a cursor object represents the number of rows affected by the last SQL command.
Q28. Which method is used to execute a multi-statement SQL script in sqlite3?
a) execute()
b) executescript()
c) execute_script()
d) execute_many()
Answer: b
Explanation: The executescript() method is used to execute a multi-statement SQL script in sqlite3.
Q29. What is the purpose of the fetchone() method in Python’s database interaction?
a) To fetch all rows from the result set
b) To fetch the next row of a query result set
c) To fetch the first row of the result set
d) To fetch a specific row based on index
Answer: c
Explanation: The fetchone() method fetches the first row of a query result set in Python’s database interaction.
Q30. Which SQL command is used to delete records from a database table?
a) DELETE FROM
b) UPDATE
c) INSERT INTO
d) SELECT
Answer: a
Explanation: The DELETE FROM SQL command is used to delete records from a database table.
Q31. What is the purpose of the rollback() method in Python’s database interaction?
a) To execute a transaction
b) To fetch results from the database
c) To undo changes made since the last commit()
d) To close the database connection
Answer: c
Explanation: The rollback() method is used to undo changes made since the last commit() in Python’s database interaction.
Q32. Which method is used to close the database connection in sqlite3?
a) close()
b) close_connection()
c) destroy()
d) connection_close()
Answer: a
Explanation: The close() method is used to close the database connection in sqlite3.
Congratulations on completing the Python Database Interaction MCQs! Database interaction is a crucial skill for many Python developers, enabling them to work with various database systems and manage data effectively. By mastering database interaction in Python, you gain the ability to connect to databases, execute queries, fetch and manipulate data, and handle transactions securely. Keep practicing and experimenting with different database libraries and techniques to become proficient in database interaction with Python. If you have any questions or want to delve deeper into any topic, don’t hesitate to continue your learning journey. Happy coding!
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