FastAPI tortoise ORM example with created_at and updated_at workaround

main.py

# pylint: disable=E0611,E0401
from typing import List
import pprint
from fastapi import FastAPI
from models import User_Pydantic, UserIn_Pydantic, Users
from pydantic import BaseModel
from starlette.exceptions import HTTPException
from datetime import datetime
from tortoise.contrib.fastapi import register_tortoise

app = FastAPI(title="Tortoise ORM FastAPI example")


class Status(BaseModel):
    message: str


@app.get("/users", response_model=List[User_Pydantic])
async def get_users():
    return await User_Pydantic.from_queryset(Users.all())


@app.post("/users", response_model=User_Pydantic)
async def create_user(user: UserIn_Pydantic):
    user_obj = await Users.create(**user.dict(exclude_unset=True))
    return await User_Pydantic.from_tortoise_orm(user_obj)


@app.get("/user/{user_id}", response_model=User_Pydantic)
async def get_user(user_id: int):
    return await User_Pydantic.from_queryset_single(Users.get(id=user_id))


@app.put("/user/{user_id}", response_model=User_Pydantic)
async def update_user(user_id: int, user: UserIn_Pydantic):
    existing_data = await User_Pydantic.from_queryset_single(Users.get(id=user_id))
    previous_data = existing_data.model_dump()

    user_data = user.dict(exclude_unset=True)
    # Here we override the timestamps 
    user_data["modified_at"] = datetime.utcnow()
    user_data["created_at"] = previous_data["created_at"]
    pprint.pprint(user_data)
    
    await Users.filter(id=user_id).update(**user_data)
    return await User_Pydantic.from_queryset_single(Users.get(id=user_id))


@app.delete("/user/{user_id}", response_model=Status)
async def delete_user(user_id: int):
    deleted_count = await Users.filter(id=user_id).delete()
    if not deleted_count:
        raise HTTPException(status_code=404, detail=f"User {user_id} not found")
    return Status(message=f"Deleted user {user_id}")


register_tortoise(
    app,
    db_url="sqlite://db.sqlite3",
    modules={"models": ["models"]},
    generate_schemas=True,
    add_exception_handlers=True,
)

models.py

from tortoise import fields, models
from tortoise.contrib.pydantic import pydantic_model_creator


class Users(models.Model):
    """
    The User model
    """

    id = fields.IntField(pk=True)
    #: This is a username
    username = fields.CharField(max_length=20, unique=False)
    name = fields.CharField(max_length=50, null=True)
    family_name = fields.CharField(max_length=50, null=True)
    category = fields.CharField(max_length=30, default="misc")
    password_hash = fields.CharField(max_length=128, null=True)
    created_at = fields.DatetimeField(auto_now_add=True)
    modified_at = fields.DatetimeField(auto_now=True, null=True)

    def full_name(self) -> str:
        """
        Returns the best name
        """
        if self.name or self.family_name:
            return f"{self.name or ''} {self.family_name or ''}".strip()
        return self.username

    class PydanticMeta:
        computed = ["full_name"]
        exclude = ["password_hash"]


User_Pydantic = pydantic_model_creator(Users, name="User")
# Make sure to exclude `created_at` and `modified_at` to make pydantic happy as of now. Maybe it will be fixed later.
# https://docs.pydantic.dev/2.3/errors/validation_errors/#missing
UserIn_Pydantic = pydantic_model_creator(
    Users, name="UserIn", exclude=["created_at", "modified_at"], exclude_readonly=True
)