What is SQLAlchemy ORM and how does it work?

What is SQLAlchemy ORM and how does it work?

SQLAlchemy ORM is an Object Relational Mapper that allows you to interact with databases using Python objects. It abstracts the database interactions and lets you work with Python classes and objects instead of SQL queries.

Can you give me an example of how to define a model using SQLAlchemy ORM?

Sure! Here's a simple example:

from sqlalchemy import Column, Integer, String, create_engine
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import sessionmaker

Base = declarative_base()

class User(Base):
    __tablename__ = 'users'
    id = Column(Integer, primary_key=True)
    name = Column(String)
    age = Column(Integer)

engine = create_engine('sqlite:///:memory:')
Base.metadata.create_all(engine)

How do I query data using SQLAlchemy ORM?

You can query data using the session object. For example:

Session = sessionmaker(bind=engine)
session = Session()

# Query all users
users = session.query(User).all()
for user in users:
    print(user.name)

What are some advantages of using SQLAlchemy ORM?

Some advantages include:

1. Abstraction of SQL queries.
2. Easy to manage relationships between tables.
3. Supports multiple database backends.
4. Provides a powerful query language.