SQLAlchemy is a popular Python library that provides an Object-Relational Mapping (ORM) tool for working with relational databases. It allows you to interact with databases using Python objects and provides a high-level, abstracted interface to perform CRUD (Create, Read, Update, Delete) operations without writing raw SQL queries.
Overview of SQLAlchemy:
Most common methods in SQLAlchemy (ORM):
session.add(): Adds an object to the session’s unit of work, meaning it will be persisted to the database upon committing the session.
session.query(): Creates a new query object that allows you to fetch data from the database using Pythonic syntax.
session.commit(): Commits the current transaction to the database, making the changes permanent.
session.rollback(): Rolls back the current transaction, undoing any changes made since the last commit.
session.delete(): Marks an object for deletion in the database. The object will be deleted upon committing the session.
session.merge(): Merges changes from a detached object into the session’s unit of work, updating the corresponding object in the database.
session.expunge(): Removes an object from the session, making it “detached” from the session and no longer tracked for changes.
session.query.filter(): Adds filtering criteria to the query to retrieve specific data from the database.
session.query.join(): Performs a join operation between two or more tables in the database.
These are just a few of the common methods provided by SQLAlchemy. The library is quite extensive and offers many more features for working with databases in Python.