Chapter 17: Python Meets SQL
17.7 Practical Exercises of Chapter 17: Python Meets SQL
Exercise 17.7.1
Connect to the SQLite database exercise.db (you may need to create it first), create a table named students with the columns id, name, and age, then insert the following records:
students = [
(1, 'John Doe', 20),
(2, 'Jane Doe', 22),
(3, 'Mike Smith', 19),
(4, 'Alice Johnson', 21)
]Remember to close your database connection after performing these operations.
Exercise 17.7.2
Using the same students table you created in the previous exercise, write a Python function that receives a student's ID as a parameter and returns the student's name. Make sure to handle any exceptions that might occur if the ID is not found in the table.
Exercise 17.7.3
Update the age of 'John Doe' in the students table to 25 using Python and the sqlite3 module. Verify your update by querying the table.
Exercise 17.7.4
Write a Python function to delete a student record from the students table based on the student's ID. Remember to handle exceptions if the student ID does not exist.
Exercise 17.7.5
Write a Python script using psycopg2 module to connect to your PostgreSQL database. Create a table named employees with the fields id, first_name, last_name, department and salary. Populate the table with some data of your choice.
Exercise 17.7.6
Using the employees table you created in the previous exercise, write Python functions to do the following:
- A function to increase the salary of an employee based on their ID.
- A function to fetch and print all employees working in a specific department.
Remember to handle any exceptions that may occur.
Note: For exercises involving SQLite, you can run them on any system where Python is installed. However, exercises involving PostgreSQL require a PostgreSQL server to be installed and running on your system. If you're unable to install PostgreSQL, you can use an online SQL platform that supports PostgreSQL, or you can adapt the exercises to use SQLite instead.
Chapter 17 Conclusion
In this chapter, we've taken an in-depth look at how Python interacts with SQL databases using various libraries such as sqlite3, psycopg2, and mysql-connector-python. We started by discussing the sqlite3 module and how it can be used to connect to SQLite databases, execute SQL queries, and fetch results. We then explained how to use Python's DB-API 2.0 interface to interact with different types of databases.
We went over the basic CRUD (Create, Read, Update, Delete) operations and how they can be performed on a database using Python. Along the way, we also learned about the importance of handling transactions in Python, which can significantly impact the consistency and integrity of our database.
We then delved into error and exception handling, which is a crucial aspect of writing robust, error-free code. We looked at some of the common exceptions that can arise when working with SQL in Python and learned how to handle them.
Throughout the chapter, we kept the discussions practical and hands-on, providing numerous examples and exercises to help you understand and apply the concepts we've covered. By working through these exercises, you have hopefully gained a firm grasp of the power and flexibility that Python provides for SQL database interactions.
In conclusion, SQL is a powerful tool for managing and manipulating structured data, and Python provides a flexible and efficient way to leverage this power. Whether you're working with a small SQLite database or a large-scale PostgreSQL or MySQL database, Python has the tools and libraries you need to interact with your data effectively and efficiently. In the next chapter, we will explore how Python can be used with NoSQL databases, expanding our data management capabilities even further.
Remember, practice is key when it comes to learning and mastering these concepts, so don't hesitate to experiment and build your own projects using Python and SQL. Happy coding!
17.7 Practical Exercises of Chapter 17: Python Meets SQL
Exercise 17.7.1
Connect to the SQLite database exercise.db (you may need to create it first), create a table named students with the columns id, name, and age, then insert the following records:
students = [
(1, 'John Doe', 20),
(2, 'Jane Doe', 22),
(3, 'Mike Smith', 19),
(4, 'Alice Johnson', 21)
]Remember to close your database connection after performing these operations.
Exercise 17.7.2
Using the same students table you created in the previous exercise, write a Python function that receives a student's ID as a parameter and returns the student's name. Make sure to handle any exceptions that might occur if the ID is not found in the table.
Exercise 17.7.3
Update the age of 'John Doe' in the students table to 25 using Python and the sqlite3 module. Verify your update by querying the table.
Exercise 17.7.4
Write a Python function to delete a student record from the students table based on the student's ID. Remember to handle exceptions if the student ID does not exist.
Exercise 17.7.5
Write a Python script using psycopg2 module to connect to your PostgreSQL database. Create a table named employees with the fields id, first_name, last_name, department and salary. Populate the table with some data of your choice.
Exercise 17.7.6
Using the employees table you created in the previous exercise, write Python functions to do the following:
- A function to increase the salary of an employee based on their ID.
- A function to fetch and print all employees working in a specific department.
Remember to handle any exceptions that may occur.
Note: For exercises involving SQLite, you can run them on any system where Python is installed. However, exercises involving PostgreSQL require a PostgreSQL server to be installed and running on your system. If you're unable to install PostgreSQL, you can use an online SQL platform that supports PostgreSQL, or you can adapt the exercises to use SQLite instead.
Chapter 17 Conclusion
In this chapter, we've taken an in-depth look at how Python interacts with SQL databases using various libraries such as sqlite3, psycopg2, and mysql-connector-python. We started by discussing the sqlite3 module and how it can be used to connect to SQLite databases, execute SQL queries, and fetch results. We then explained how to use Python's DB-API 2.0 interface to interact with different types of databases.
We went over the basic CRUD (Create, Read, Update, Delete) operations and how they can be performed on a database using Python. Along the way, we also learned about the importance of handling transactions in Python, which can significantly impact the consistency and integrity of our database.
We then delved into error and exception handling, which is a crucial aspect of writing robust, error-free code. We looked at some of the common exceptions that can arise when working with SQL in Python and learned how to handle them.
Throughout the chapter, we kept the discussions practical and hands-on, providing numerous examples and exercises to help you understand and apply the concepts we've covered. By working through these exercises, you have hopefully gained a firm grasp of the power and flexibility that Python provides for SQL database interactions.
In conclusion, SQL is a powerful tool for managing and manipulating structured data, and Python provides a flexible and efficient way to leverage this power. Whether you're working with a small SQLite database or a large-scale PostgreSQL or MySQL database, Python has the tools and libraries you need to interact with your data effectively and efficiently. In the next chapter, we will explore how Python can be used with NoSQL databases, expanding our data management capabilities even further.
Remember, practice is key when it comes to learning and mastering these concepts, so don't hesitate to experiment and build your own projects using Python and SQL. Happy coding!
17.7 Practical Exercises of Chapter 17: Python Meets SQL
Exercise 17.7.1
Connect to the SQLite database exercise.db (you may need to create it first), create a table named students with the columns id, name, and age, then insert the following records:
students = [
(1, 'John Doe', 20),
(2, 'Jane Doe', 22),
(3, 'Mike Smith', 19),
(4, 'Alice Johnson', 21)
]Remember to close your database connection after performing these operations.
Exercise 17.7.2
Using the same students table you created in the previous exercise, write a Python function that receives a student's ID as a parameter and returns the student's name. Make sure to handle any exceptions that might occur if the ID is not found in the table.
Exercise 17.7.3
Update the age of 'John Doe' in the students table to 25 using Python and the sqlite3 module. Verify your update by querying the table.
Exercise 17.7.4
Write a Python function to delete a student record from the students table based on the student's ID. Remember to handle exceptions if the student ID does not exist.
Exercise 17.7.5
Write a Python script using psycopg2 module to connect to your PostgreSQL database. Create a table named employees with the fields id, first_name, last_name, department and salary. Populate the table with some data of your choice.
Exercise 17.7.6
Using the employees table you created in the previous exercise, write Python functions to do the following:
- A function to increase the salary of an employee based on their ID.
- A function to fetch and print all employees working in a specific department.
Remember to handle any exceptions that may occur.
Note: For exercises involving SQLite, you can run them on any system where Python is installed. However, exercises involving PostgreSQL require a PostgreSQL server to be installed and running on your system. If you're unable to install PostgreSQL, you can use an online SQL platform that supports PostgreSQL, or you can adapt the exercises to use SQLite instead.
Chapter 17 Conclusion
In this chapter, we've taken an in-depth look at how Python interacts with SQL databases using various libraries such as sqlite3, psycopg2, and mysql-connector-python. We started by discussing the sqlite3 module and how it can be used to connect to SQLite databases, execute SQL queries, and fetch results. We then explained how to use Python's DB-API 2.0 interface to interact with different types of databases.
We went over the basic CRUD (Create, Read, Update, Delete) operations and how they can be performed on a database using Python. Along the way, we also learned about the importance of handling transactions in Python, which can significantly impact the consistency and integrity of our database.
We then delved into error and exception handling, which is a crucial aspect of writing robust, error-free code. We looked at some of the common exceptions that can arise when working with SQL in Python and learned how to handle them.
Throughout the chapter, we kept the discussions practical and hands-on, providing numerous examples and exercises to help you understand and apply the concepts we've covered. By working through these exercises, you have hopefully gained a firm grasp of the power and flexibility that Python provides for SQL database interactions.
In conclusion, SQL is a powerful tool for managing and manipulating structured data, and Python provides a flexible and efficient way to leverage this power. Whether you're working with a small SQLite database or a large-scale PostgreSQL or MySQL database, Python has the tools and libraries you need to interact with your data effectively and efficiently. In the next chapter, we will explore how Python can be used with NoSQL databases, expanding our data management capabilities even further.
Remember, practice is key when it comes to learning and mastering these concepts, so don't hesitate to experiment and build your own projects using Python and SQL. Happy coding!
17.7 Practical Exercises of Chapter 17: Python Meets SQL
Exercise 17.7.1
Connect to the SQLite database exercise.db (you may need to create it first), create a table named students with the columns id, name, and age, then insert the following records:
students = [
(1, 'John Doe', 20),
(2, 'Jane Doe', 22),
(3, 'Mike Smith', 19),
(4, 'Alice Johnson', 21)
]Remember to close your database connection after performing these operations.
Exercise 17.7.2
Using the same students table you created in the previous exercise, write a Python function that receives a student's ID as a parameter and returns the student's name. Make sure to handle any exceptions that might occur if the ID is not found in the table.
Exercise 17.7.3
Update the age of 'John Doe' in the students table to 25 using Python and the sqlite3 module. Verify your update by querying the table.
Exercise 17.7.4
Write a Python function to delete a student record from the students table based on the student's ID. Remember to handle exceptions if the student ID does not exist.
Exercise 17.7.5
Write a Python script using psycopg2 module to connect to your PostgreSQL database. Create a table named employees with the fields id, first_name, last_name, department and salary. Populate the table with some data of your choice.
Exercise 17.7.6
Using the employees table you created in the previous exercise, write Python functions to do the following:
- A function to increase the salary of an employee based on their ID.
- A function to fetch and print all employees working in a specific department.
Remember to handle any exceptions that may occur.
Note: For exercises involving SQLite, you can run them on any system where Python is installed. However, exercises involving PostgreSQL require a PostgreSQL server to be installed and running on your system. If you're unable to install PostgreSQL, you can use an online SQL platform that supports PostgreSQL, or you can adapt the exercises to use SQLite instead.
Chapter 17 Conclusion
In this chapter, we've taken an in-depth look at how Python interacts with SQL databases using various libraries such as sqlite3, psycopg2, and mysql-connector-python. We started by discussing the sqlite3 module and how it can be used to connect to SQLite databases, execute SQL queries, and fetch results. We then explained how to use Python's DB-API 2.0 interface to interact with different types of databases.
We went over the basic CRUD (Create, Read, Update, Delete) operations and how they can be performed on a database using Python. Along the way, we also learned about the importance of handling transactions in Python, which can significantly impact the consistency and integrity of our database.
We then delved into error and exception handling, which is a crucial aspect of writing robust, error-free code. We looked at some of the common exceptions that can arise when working with SQL in Python and learned how to handle them.
Throughout the chapter, we kept the discussions practical and hands-on, providing numerous examples and exercises to help you understand and apply the concepts we've covered. By working through these exercises, you have hopefully gained a firm grasp of the power and flexibility that Python provides for SQL database interactions.
In conclusion, SQL is a powerful tool for managing and manipulating structured data, and Python provides a flexible and efficient way to leverage this power. Whether you're working with a small SQLite database or a large-scale PostgreSQL or MySQL database, Python has the tools and libraries you need to interact with your data effectively and efficiently. In the next chapter, we will explore how Python can be used with NoSQL databases, expanding our data management capabilities even further.
Remember, practice is key when it comes to learning and mastering these concepts, so don't hesitate to experiment and build your own projects using Python and SQL. Happy coding!