Exposing a JSON field from SQLModel to Strawberry

[martarho]

Hi everyone,

I'm currently working with a postgresql database which contains a table with a JSONB field. I modelled it with SQLModel, and I'm trying to apply on top Strawberry to explose the data through GraphQL.

The problem is dictionaries are not an accepted type on the graphql side. What's the recommended way one should deal with these cases? I'm currently learning both SQLModel and Strawberry, so if someone can show me an example it would be grand!

#
# Strawberry schema
#
class MyModel(SQLModel, table=True):
    id: int
    name: str
    jsonfield: dict = Field(sa_column=Column(JSON), default={"all": "true"})

@strawberry.experimental.pydantic.type(
    MyModel,
    fields=[
        "id",
       "name",
       "jsonfield"
    ],
)
class MyModelGQL:
    pass

[patrick91]

hey @martarho 😊 You'd need to create a custom scalar and then use that in your GraphQL type:

JSON = scalar(
    NewType("JSON", object),  # mypy doesn't like `NewType("name", Any)`
    description="The `JSON` scalar type represents JSON values as specified by"
    " [ECMA-404](http://www.ecma-international.org"
    "/publications/files/ECMA-ST/ECMA-404.pdf).",
    specified_by_url="http://www.ecma-international.org"
    "/publications/files/ECMA-ST/ECMA-404.pdf",
    serialize=lambda v: v,
    parse_value=lambda v: v,
)

@strawberry.experimental.pydantic.type(
    MyModel
)
class MyModelGQL:
    id: auto
    name: auto
    jsonfield: JSON

note, we'll be adding the JSON scalar soon (hopefully later today) see: #1647

[martarho]

Hi @patrick91 , thanks! <3 that makes sense! And thanks for the link, I'll watch that issue!