lily_website

📜 Base

⬅️ Back

🏠 Docs Root

This module defines the base classes and conventions for SQLAlchemy models used in the Telegram Bot’s direct database mode. It ensures consistent naming conventions for Alembic migrations and provides a mixin for common timestamp fields.

Naming Convention (convention)

convention = {
    "ix": "ix_%(column_0_label)s",
    "uq": "uq_%(table_name)s_%(column_0_name)s",
    "ck": "ck_%(table_name)s_%(constraint_name)s",
    "fk": "fk_%(table_name)s_%(column_0_name)s_%(referred_table_name)s",
    "pk": "pk_%(table_name)s",
}

This dictionary defines a naming convention for database objects (indexes, unique constraints, check constraints, foreign keys, primary keys). This convention is crucial for generating consistent and predictable names in Alembic database migrations, simplifying schema management.

Base Class

class Base(DeclarativeBase):
    """Base class for all Bot SQLAlchemy models."""
    metadata = MetaData(naming_convention=convention)

This is the declarative base class for all SQLAlchemy models in the bot application. All models should inherit from this Base class.

• metadata: An instance of MetaData configured with the convention dictionary, ensuring that all models inheriting from Base adhere to the defined naming conventions.

TimestampMixin

class TimestampMixin:
    """Mixin to add created_at and updated_at columns."""
    created_at: Mapped[datetime] = mapped_column(server_default=func.now(), nullable=False)
    updated_at: Mapped[datetime] = mapped_column(server_default=func.now(), onupdate=func.now(), nullable=False)

A mixin class that provides created_at and updated_at columns to any SQLAlchemy model it is included in.

• created_at: A datetime column that automatically records the creation timestamp of a record. It defaults to the current time on the server.
• updated_at: A datetime column that automatically updates to the current time on the server whenever the record is modified.