Building SQLAlchemy Objects
In this chapter, you'll learn how to set up your database session and add data to the database using SQLAlchemy. By the end, you'll understand how to create a session, add a new record, and save it. After creating the model, you can proceed to creating objects and saving them to the database.
Session in SQLAlchemy is a tool for interacting with a database, where you can add, modify, or delete data. All these changes are first stored in the session, and then, when you're ready, they are committed to the database.
1. Set Up the Session
A session is your primary tool for interacting with the database. Use sessionmaker to bind the engine and create a session:
Session = sessionmaker(bind=engine)
session = Session()
The Session() function creates an active session that serves as a workspace for staging and preparing database operations before they are committed.
2. Add a New Object
To add data, follow these steps:
- Create an Object
Instantiate a model class (e.g.,Product) with the required attributes.new_product = Product(name="Laptop", description="High-end gaming laptop", price=1500) - Stage the Object
Add the object to the session withadd().session.add(new_product) - Save the Changes
Commit the session to finalize the transaction.session.commit()
When you use add(), the object is staged in the session, meaning it's prepared for saving but won't be written to the database until you call commit(), which finalizes all changes made in the session.
Swipe to start coding
- Initialize the database session using
Session. - Create a new object of the
Productclass with the specified attributes. - Add the new object to the session using the appropriate method.
- Commit the transaction to save changes to the database.
Solution
Thanks for your feedback!
single
Ask AI
Ask AI
Ask anything or try one of the suggested questions to begin our chat
Can you explain what a session is in SQLAlchemy?
What happens if I forget to commit the session?
How do I handle errors when adding data to the database?
Awesome!
Completion rate improved to 4.76Building SQLAlchemy Objects
Swipe to show menu
In this chapter, you'll learn how to set up your database session and add data to the database using SQLAlchemy. By the end, you'll understand how to create a session, add a new record, and save it. After creating the model, you can proceed to creating objects and saving them to the database.
Session in SQLAlchemy is a tool for interacting with a database, where you can add, modify, or delete data. All these changes are first stored in the session, and then, when you're ready, they are committed to the database.
1. Set Up the Session
A session is your primary tool for interacting with the database. Use sessionmaker to bind the engine and create a session:
Session = sessionmaker(bind=engine)
session = Session()
The Session() function creates an active session that serves as a workspace for staging and preparing database operations before they are committed.
2. Add a New Object
To add data, follow these steps:
- Create an Object
Instantiate a model class (e.g.,Product) with the required attributes.new_product = Product(name="Laptop", description="High-end gaming laptop", price=1500) - Stage the Object
Add the object to the session withadd().session.add(new_product) - Save the Changes
Commit the session to finalize the transaction.session.commit()
When you use add(), the object is staged in the session, meaning it's prepared for saving but won't be written to the database until you call commit(), which finalizes all changes made in the session.
Swipe to start coding
- Initialize the database session using
Session. - Create a new object of the
Productclass with the specified attributes. - Add the new object to the session using the appropriate method.
- Commit the transaction to save changes to the database.
Solution
Switch to desktop for real-world practiceContinue from where you are using one of the options belowThanks for your feedback!
single
