1.4 to 2.0 Migration

SQLAlchemy 2.0, released in January 2023, adopts a unified execution style. Queries move from session.query() to session.execute(select(...)). Version 1.4 served as a migration bridge supporting both styles.

Before / After

python 
from sqlalchemy import select, create_engine
from sqlalchemy.orm import Session, DeclarativeBase, Mapped, mapped_column

class Base(DeclarativeBase):
    pass

class User(Base):
    __tablename__ = 'users'
    id: Mapped[int] = mapped_column(primary_key=True)
    name: Mapped[str]

# SQLAlchemy 1.x: session.query(User).filter_by(name='Alice').first()

# SQLAlchemy 2.0:
engine = create_engine('sqlite:///db.sqlite3')
with Session(engine) as session:
    stmt = select(User).where(User.name == 'Alice')
    user = session.execute(stmt).scalar_one_or_none()
    print(user)

Sources