from sqlmodel import SQLModel, Field


class SongBase(SQLModel):
    """
    SongBase is the base model that the others inherit from.
    It has two properties, name and artist, both of which are strings.
    This is a data-only model since it lacks table=True, which means
    that it's only used as a pydantic model
    """
    name: str
    artist: str


class Song(SongBase, table=True):
    """
    Song, meanwhile, adds an id property to the base model. It's a table model,
     so it's a pydantic and SQLAlchemy model. It represents a database table.
    """
    id: int = Field(default=None, primary_key=True)


class SongCreate(SongBase):
    """
    SongCreate is a data-only, pydantic model
     that will be used to create new song instances.
    """
    pass