[Idea] SQLAlchemy model code generator

[SaintRyoh]

I'm using erd-editor as the design-first step in a FastAPI + PostgreSQL workflow. The code generator already covers DDL for the major SQL dialects which is great, but my next step after designing the schema is writing SQLAlchemy models. Currently I have to either write them by hand or run sqlacodegen against a live database.

A SQLAlchemy generator would close this loop entirely:

erd-editor → DDL + SQLAlchemy models → Alembic autogenerate → migrations

Looking at the existing code generator structure, it seems like this would follow the same pattern as the existing dialect .ts files, just outputting Python class definitions instead of SQL. For example, given a users table it would output something like:

Example

CREATE TABLE users
(
  id             uuid        NOT NULL DEFAULT gen_random_uuid(),
  google_sub     text        NOT NULL UNIQUE,
  email          text        NOT NULL UNIQUE,
  email_verified boolean     NOT NULL DEFAULT false,
  created_at     timestamptz NOT NULL DEFAULT now(),
  last_login_at  timestamptz NOT NULL DEFAULT now(),
  PRIMARY KEY (id)
);

COMMENT ON TABLE users IS 'Stores authenticated users. Keyed on Google's sub claim.';

COMMENT ON COLUMN users.id IS 'internal private key';

COMMENT ON COLUMN users.google_sub IS 'Google's immutable user identifier from the `sub` claim';

COMMENT ON COLUMN users.email IS 'updated on every login in case user changes it';

COMMENT ON COLUMN users.email_verified IS 'from Google token, always true for Google auth';

COMMENT ON COLUMN users.created_at IS 'set once on provisioning, never updated';

COMMENT ON COLUMN users.last_login_at IS 'updated on every login';

"""ORM model for the users table."""

import uuid
from datetime import datetime

from sqlalchemy import Boolean, DateTime, Text, text
from sqlalchemy.dialects.postgresql import UUID
from sqlalchemy.orm import Mapped, mapped_column
from sqlalchemy.sql import func

from app.db.base import Base


class User(Base):
    """Represents a user who has authenticated via Google OAuth2."""

    __tablename__ = "users"

    id: Mapped[uuid.UUID] = mapped_column(
        UUID(as_uuid=True),
        primary_key=True,
        server_default=text("gen_random_uuid()"),
    )
    google_sub: Mapped[str] = mapped_column(Text, nullable=False, unique=True)
    email: Mapped[str] = mapped_column(Text, nullable=False, unique=True)
    email_verified: Mapped[bool] = mapped_column(
        Boolean, nullable=False, server_default=text("false")
    )
    created_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), nullable=False, server_default=func.now()
    )
    last_login_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), nullable=False, server_default=func.now()
    )

Happy to contribute this if pointed to the right place in the codebase.

[dineug]

#426