Unable to save a Piccolo table and serialize it.

[arunk]

Hi, I've created a blacksheep project and I'm trying to integrate piccolo into it. I have created a sample project with piccolo asgi new for reference. I have created a piccolo app, and added it to the APP_REGISTRY in piccolo_conf.py and inside the app I have defined a model that looks like this:

class UrlMap(Table):
    url = Text(index=True)
    code = Varchar(length=30, unique=True, required=True)
    out_url = Varchar(length=64)
    date_created = Timestamp(default=datetime.datetime.now)
    date_expired = Timestamp(null=True)
    use_count = SmallInt(default=0)
    max_uses = SmallInt()
    lifespan = SmallInt()

I have created pydantic models using the create_pydantic_model from piccolo_api.crud.serializers and created UrlMapPartial and UrlMapOut. In my create post endpoint, I am setting the default values for all the fields on UrlMap, and doing a urlmap.save(). But when I try and return UrlMapOut(**urlmap.to_dict()), I get the following error stack:

Traceback (most recent call last):
  File "blacksheep/baseapp.pyx", line 81, in blacksheep.baseapp.BaseApplication.handle
  File "/home/arun/Projects/zite69/z69.in/venv/lib/python3.12/site-packages/blacksheep/server/normalization.py", line 682, in handler
    return ensure_response(await method(request))
                           ^^^^^^^^^^^^^^^^^^^^^
  File "/home/arun/Projects/zite69/z69.in/venv/lib/python3.12/site-packages/blacksheep/server/normalization.py", line 524, in handler
    response = await method(*values)
               ^^^^^^^^^^^^^^^^^^^^^
  File "/home/arun/Projects/zite69/z69.in/app/controllers/home.py", line 61, in create
    return UrlMapOut(**urlmap.to_dict())
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/arun/Projects/zite69/z69.in/venv/lib/python3.12/site-packages/pydantic/main.py", line 212, in __init__
    validated_self = self.__pydantic_validator__.validate_python(data, self_instance=self)
                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
pydantic_core._pydantic_core.ValidationError: 1 validation error for UrlMapOut
id
  Input should be a valid integer [type=int_type, input_value=<piccolo.querystring.Quer...bject at 0x7aca29829de0>, input_type=QueryString]
    For further information visit https://errors.pydantic.dev/2.9/v/int_type

When I dump out my urlmap variable it looks like this:

{'id': <piccolo.querystring.QueryString object at 0x7aca29829de0>, 'url': 'https://www.zite69.com/invitation/abcdefghijko124334', 'code': '5e550d0b', 'out_url': 'https://z69.in/5e550d0b', 'date_created': datetime.datetime(2024, 10, 5, 4, 8, 33, 229052), 'date_expired': None, 'usage_count': 0, 'max_uses': -1, 'lifespan': -1}

It seems like the field 'id' instead of being automatically set to an integer, is being given this QueryString object instance. Could someone please tell me the right way to do this? I've gone through the docs, and it just says you save and it should work. I'm using sqlite database btw.

[dantownsend]

I think the problem is that you didn't save your object.

For example, if you try piccolo playground run locally, and then run this:

>>> foo = Band()
>>> foo.to_dict()
{'id': <piccolo.querystring.QueryString at 0x105fe4460>,
 'name': '',
 'manager': None,
 'popularity': 0}

Which is basically the same as what you got.

But if you do the save call, then it works OK:

>>> foo = Band()
>>> await foo.save()
>>> foo.to_dict()
{'id': 4, 'name': '', 'manager': None, 'popularity': 0}

[arunk]

Thanks, I just found this, I was calling save but not awaiting it.