SQLAlchemy is a Python SQL toolkit and ORM framework

Provides comprehensive database operations and ORM functions

Supports multiple databases, such as MySQL, PostgreSQL, SQLite, etc.

Install SQLAlchemy using pip

Installation command: pip install SQLAlchemy

Create a database connection using the create_engine function

Example: engine = create_engine('mysql://user:password@localhost/dbname')

Use the declarative_base function to create a model base class

Use a class to inherit the model base class and define properties

Example: from sqlalchemy import Column, Integer, String

class User(Base):

Use Base.metadata.create_all() to map the model to the database

Example: Base.metadata.create_all(engine)

Use session.add() to add new objects to the session

Use ***mit() to commit the session

Example: from sqlalchemy.orm import sessionmaker

Session = sessionmaker(bind=engine)

session = Session()

new_user = User(name='John')

session.add(new_user)

***mit()

Use session.query() to construct a query object

Query using the filter method on the query object

Example: users = session.query(User).filter_by(name='John').all()

Use session.query() to construct a query object

Update using the update method on the query object

Example: user = session.query(User).filter_by(name='John').first()

user.name = 'Jane'

***mit()

Use session.query() to construct a query object

Delete using delete method on query object

Example: user = session.query(User).filter_by(name='Jane').first()

session.delete(user)

***mit()

one-to-one relationship

one-to-many relationship

many-to-many relationship

Use join query instead of subquery

Use batch insert instead of single insert

Use indexes to improve query speed

Use try/except to handle database operation exceptions

Example: try:

except Exception as e: