✨ Add support for all Field parameters from Pydantic version 1.9.0

(incl. `max_digits`, `decimal_places`, `unique_items`, `discriminator`, and `repr`);
add tests for Pydantic capabilities;
bump Pydantic dependency to `1.9.0`

Author: daniil-berg

pyproject.toml

@@ -32,7 +32,7 @@ classifiers = [
 [tool.poetry.dependencies]
 python = "^3.6.1"
 SQLAlchemy = ">=1.4.17,<=1.4.41"
-pydantic = "^1.8.2"
+pydantic = "^1.9.0"
 sqlalchemy2-stubs = {version = "*", allow-prereleases = true}
 
 [tool.poetry.dev-dependencies]

sqlmodel/main.py

@@ -135,12 +135,17 @@ def Field(
     lt: Optional[float] = None,
     le: Optional[float] = None,
     multiple_of: Optional[float] = None,
+    max_digits: Optional[int] = None,
+    decimal_places: Optional[int] = None,
     min_items: Optional[int] = None,
     max_items: Optional[int] = None,
+    unique_items: Optional[bool] = None,
     min_length: Optional[int] = None,
     max_length: Optional[int] = None,
     allow_mutation: bool = True,
     regex: Optional[str] = None,
+    discriminator: Optional[str] = None,
+    repr: bool = True,
     primary_key: bool = False,
     foreign_key: Optional[Any] = None,
     unique: bool = False,
@@ -166,12 +171,17 @@ def Field(
         lt=lt,
         le=le,
         multiple_of=multiple_of,
+        max_digits=max_digits,
+        decimal_places=decimal_places,
         min_items=min_items,
         max_items=max_items,
+        unique_items=unique_items,
         min_length=min_length,
         max_length=max_length,
         allow_mutation=allow_mutation,
         regex=regex,
+        discriminator=discriminator,
+        repr=repr,
         primary_key=primary_key,
         foreign_key=foreign_key,
         unique=unique,
@@ -576,7 +586,11 @@ def parse_obj(
 
     def __repr_args__(self) -> Sequence[Tuple[Optional[str], Any]]:
         # Don't show SQLAlchemy private attributes
-        return [(k, v) for k, v in self.__dict__.items() if not k.startswith("_sa_")]
+        return [
+            (k, v)
+            for k, v in super().__repr_args__()
+            if not (isinstance(k, str) and k.startswith("_sa_"))
+        ]
 
     # From Pydantic, override to enforce validation with dict
     @classmethod

tests/test_pydantic/__init__.py

@@ -0,0 +1,69 @@
+"""
+Tests to ensure that the SQLModel `Field` constructor works as
+expected from the Pydantic `Field` function.
+"""
+from decimal import Decimal
+from typing import List, Literal, Optional, Union
+
+import pytest
+from pydantic import ValidationError
+from sqlmodel import Field, SQLModel
+
+
+def test_decimal():
+    class Model(SQLModel):
+        dec: Decimal = Field(max_digits=4, decimal_places=2)
+
+    Model(dec=Decimal("3.14"))
+    Model(dec=Decimal("69.42"))
+
+    with pytest.raises(ValidationError):
+        Model(dec=Decimal("3.142"))
+    with pytest.raises(ValidationError):
+        Model(dec=Decimal("0.069"))
+    with pytest.raises(ValidationError):
+        Model(dec=Decimal("420"))
+
+
+def test_unique_items():
+    class Model(SQLModel):
+        unique_strings: List[str] = Field(unique_items=True)
+
+    Model(unique_strings=["x", "y"])
+
+    with pytest.raises(ValidationError):
+        Model(unique_strings=["x", "y", "x"])
+
+
+def test_discriminator():
+    # Example adapted from
+    # [Pydantic docs](https://pydantic-docs.helpmanual.io/usage/types/#discriminated-unions-aka-tagged-unions):
+    class Cat(SQLModel):
+        pet_type: Literal["cat"]
+        meows: int
+
+    class Dog(SQLModel):
+        pet_type: Literal["dog"]
+        barks: float
+
+    class Lizard(SQLModel):
+        pet_type: Literal["reptile", "lizard"]
+        scales: bool
+
+    class Model(SQLModel):
+        pet: Union[Cat, Dog, Lizard] = Field(..., discriminator="pet_type")
+        n: int
+
+    Model(pet={"pet_type": "dog", "barks": 3.14}, n=1)  # type: ignore[arg-type]
+
+    with pytest.raises(ValidationError):
+        Model(pet={"pet_type": "dog"}, n=1)  # type: ignore[arg-type]
+
+
+def test_repr():
+    class Model(SQLModel):
+        id: Optional[int] = Field(primary_key=True)
+        foo: str = Field(repr=False)
+
+    instance = Model(id=123, foo="bar")
+    assert "foo=" not in repr(instance)