field_validator is not supported?

[ferdousbhai]

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Example Code

from sqlmodel import SQLModel, Field, field_validator


class Market(SQLModel, table=True):
    id: int | None = Field(default=None, primary_key=True)
    question: str
    description: str
    outcomes: list[str] = Field(
        default_factory=list, description="list of possible outcomes"
    )
    outcomePrices: list[float] = Field(
        default_factory=list, description="probabilities of each outcome"
    )
    volume: float
    categories: list[str] = Field(
        default_factory=list, description="list of categories"
    )

    @field_validator("categories", mode="before")
    def extract_category_labels(cls, categories):
        if categories:
            return [category["label"] for category in categories]
        return []

    @field_validator("outcomes", "outcomePrices", mode="before")
    def parse_lists(cls, v):
        if isinstance(v, str):
            return json.loads(v)
        return v

Description

I want to pre-process some data before initializing the model. Works fine with Pydantic but seems Pydantic's 'field_validator' is missing in sqlmodel.

Operating System

Linux

Operating System Details

No response

SQLModel Version

latest

Python Version

3.11

Additional Context

No response

[northshaur]

Did you find a response separately? Facing the same issue

[joachimhuet]

Validation is not triggered when table=True by choice. See #52 for alternatives. I would suggest you to use a non table class with the validation and then inherit it from your table=True.
Like so:

class MarketBase(SQLModel):
    id: int | None = Field(default=None, primary_key=True)
    question: str
    description: str
    outcomes: list[str] = Field(
        default_factory=list, description="list of possible outcomes"
    )
    outcomePrices: list[float] = Field(
        default_factory=list, description="probabilities of each outcome"
    )
    volume: float
    categories: list[str] = Field(
        default_factory=list, description="list of categories"
    )

    @field_validator("categories", mode="before")
    def extract_category_labels(cls, categories):
        if categories:
            return [category["label"] for category in categories]
        return []

    @field_validator("outcomes", "outcomePrices", mode="before")
    def parse_lists(cls, v):
        if isinstance(v, str):
            return json.loads(v)
        return v

class Market(MarketBase, table=True): ...

MarketBase instances should now use the validation properly. And you can create a Market instance with Market.model_validate(market_base)