asyncpg driver

echo=False on engine

pool_size setting

max_overflow setting

expire_on_commit=False

AsyncGenerator return type

Async session context manager

Annotated DB alias

select() query style

scalar_one_or_none usage

scalars().all() usage

DeclarativeBase usage

Mapped type annotations

mapped_column() usage

ForeignKey with Mapped[int]

back_populates relationships

selectinload eager loading

and_() for AND conditions

or_() for OR conditions

func.count() aggregate

order_by and limit

select() 2.0 style

scalars().all() for lists

Session context manager

select() query style

and_() for combined filters

or_() for alternate conditions

scalars().all() for lists

func.count() aggregate

order_by with limit

Mapped types in models

DeclarativeBase