✨ Raise an exception when using a Pydantic field type with no matching SQLAlchemy type (#18)

Co-authored-by: Sebastián Ramírez <tiangolo@gmail.com>

tests/test_missing_type.py

@@ -0,0 +1,21 @@
+from typing import Optional
+
+import pytest
+from sqlmodel import Field, SQLModel
+
+
+def test_missing_sql_type():
+    class CustomType:
+        @classmethod
+        def __get_validators__(cls):
+            yield cls.validate
+
+        @classmethod
+        def validate(cls, v):
+            return v
+
+    with pytest.raises(ValueError):
+
+        class Item(SQLModel, table=True):
+            id: Optional[int] = Field(default=None, primary_key=True)
+            item: CustomType