db.relationship("...", secondary=..., back_populates="...")

# -*- coding: UTF-8 -*-

try:
    from typing import List
except ImportError:
    from builtins import list as List

from flask_sqlalchemy import SQLAlchemy
import sqlalchemy as sa
from sqlalchemy.orm import Mapped, mapped_column
from sqlalchemy.orm import DeclarativeBase, MappedAsDataclass


class Base(DeclarativeBase, MappedAsDataclass):
    """The base class for creating SQLAlchemy models.

    All mixins are defined in the mro list.

    All metadata of are defined as attributes.
    """


db = SQLAlchemy(model_class=Base)


roles = db.Table(
    "role_users",
    sa.Column("user_id", sa.ForeignKey("user.id"), primary_key=True),
    sa.Column("role_id", sa.ForeignKey("role.id"), primary_key=True),
)


class User(db.Model):
    id: Mapped[int] = mapped_column(primary_key=True, init=False)
    # Expression of type "RelationshipProperty[Any]" cannot be assigned to declared type "Mapped[List[Role]]"
    # "RelationshipProperty[Any]" is incompatible with "Mapped[List[Role]]"Pylance[reportAssignmentType] 
    # (https://github.com/microsoft/pyright/blob/main/docs/configuration.md#reportAssignmentType)
    roles: Mapped[List["Role"]] = db.relationship(
        "Role", secondary=roles, back_populates="users", default_factory=list
    )


class Role(db.Model):
    id: Mapped[int] = mapped_column(primary_key=True, init=False)
    # Expression of type "RelationshipProperty[Any]" cannot be assigned to declared type "Mapped[List[User]]"
    #  "RelationshipProperty[Any]" is incompatible with "Mapped[List[User]]"Pylance[reportAssignmentType] 
    # (https://github.com/microsoft/pyright/blob/main/docs/configuration.md#reportAssignmentType)
    users: Mapped[List["User"]] = db.relationship(
        "User", secondary=roles, back_populates="roles", default_factory=list
    )

# -*- coding: UTF-8 -*-

try:
    from typing import List
except ImportError:
    from builtins import list as List

import sqlalchemy as sa
from sqlalchemy.orm import Mapped, mapped_column, relationship
from sqlalchemy.orm import DeclarativeBase, MappedAsDataclass


class Base(DeclarativeBase, MappedAsDataclass):
    """The base class for creating SQLAlchemy models.

    All mixins are defined in the mro list.

    All metadata of are defined as attributes.
    """


roles = sa.Table(
    "role_users",
    Base.metadata,
    sa.Column("user_id", sa.ForeignKey("user.id"), primary_key=True),
    sa.Column("role_id", sa.ForeignKey("role.id"), primary_key=True),
)


class User(Base):
    __tablename__ = "users"
    id: Mapped[int] = mapped_column(primary_key=True, init=False)
    roles: Mapped[List["Role"]] = relationship(
        "Role", secondary=roles, back_populates="users", default_factory=list
    )


class Role(Base):
    __tablename__ = "roles"
    id: Mapped[int] = mapped_column(primary_key=True, init=False)
    users: Mapped[List["User"]] = relationship(
        "User", secondary=roles, back_populates="roles", default_factory=list
    )