test relation inheritance

ormar/fields/base.py

@@ -197,6 +197,12 @@ class BaseField(FieldInfo):
             return cls.autoincrement
         return False
 
+    @classmethod
+    def construct_contraints(cls) -> List:
+        return [sqlalchemy.schema.ForeignKey(
+            con.name, ondelete=con.ondelete, onupdate=con.onupdate
+        ) for con in cls.constraints]
+
     @classmethod
     def get_column(cls, name: str) -> sqlalchemy.Column:
         """
@@ -212,7 +218,7 @@ class BaseField(FieldInfo):
         return sqlalchemy.Column(
             cls.alias or name,
             cls.column_type,
-            *cls.constraints,
+            *cls.construct_contraints(),
             primary_key=cls.primary_key,
             nullable=cls.nullable and not cls.primary_key,
             index=cls.index,

ormar/fields/foreign_key.py

@@ -1,4 +1,5 @@
 import uuid
+from dataclasses import dataclass
 from typing import Any, List, Optional, TYPE_CHECKING, Type, Union
 
 import sqlalchemy
@@ -75,6 +76,13 @@ class UniqueColumns(UniqueConstraint):
     pass
 
 
+@dataclass
+class ForeignKeyConstraint:
+    name: str
+    ondelete: str
+    onupdate: str
+
+
 def ForeignKey(  # noqa CFQ002
         to: Type["Model"],
         *,
@@ -132,9 +140,7 @@ def ForeignKey(  # noqa CFQ002
         name=kwargs.pop("real_name", None),
         nullable=nullable,
         constraints=[
-            sqlalchemy.schema.ForeignKey(
-                fk_string, ondelete=ondelete, onupdate=onupdate
-            )
+            ForeignKeyConstraint(name=fk_string, ondelete=ondelete, onupdate=onupdate)
         ],
         unique=unique,
         column_type=to_field.column_type,

ormar/models/metaclass.py

@@ -1,3 +1,4 @@
+import copy
 import logging
 import warnings
 from typing import (
@@ -664,7 +665,18 @@ def extract_from_parents_definition(  # noqa: CCR001
                 base_class=base_class,  # type: ignore
                 attrs=attrs,
             )
-            model_fields.update(base_class.Meta.model_fields)  # type: ignore
+            parent_fields = dict()
+            table_name = attrs.get("Meta").tablename if hasattr(attrs.get("Meta"), "tablename") else attrs.get(
+                '__name__').lower() + 's'
+            for field_name, field in base_class.Meta.model_fields.items():
+                if issubclass(field, ForeignKeyField) and field.related_name:
+                    copy_field = type(field.__name__, (field,), dict(field.__dict__))
+                    copy_field.related_name = field.related_name + '_' + table_name
+                    parent_fields[field_name] = copy_field
+                else:
+                    parent_fields[field_name] = field
+
+            model_fields.update(parent_fields)  # type: ignore
         return attrs, model_fields
 
     key = "__annotations__"

tests/test_inheritance_concrete.py

@@ -82,6 +82,44 @@ class Subject(DateFieldsModel):
     category: Optional[Category] = ormar.ForeignKey(Category)
 
 
+class Person(ormar.Model):
+    class Meta:
+        metadata = metadata
+        database = db
+
+    id: int = ormar.Integer(primary_key=True)
+    name: str = ormar.String(max_length=100)
+
+
+class Car(ormar.Model):
+    class Meta:
+        abstract = True
+        metadata = metadata
+        database = db
+
+    id: int = ormar.Integer(primary_key=True)
+    name: str = ormar.String(max_length=50)
+    owner: Person = ormar.ForeignKey(Person)
+    co_owner: Person = ormar.ForeignKey(Person, related_name='coowned')
+
+
+class Truck(Car):
+    class Meta:
+        metadata = metadata
+        database = db
+
+    max_capacity: int = ormar.Integer()
+
+
+class Bus(Car):
+    class Meta:
+        tablename = 'buses'
+        metadata = metadata
+        database = db
+
+    max_persons: int = ormar.Integer()
+
+
 @pytest.fixture(autouse=True, scope="module")
 def create_test_database():
     metadata.create_all(engine)
@@ -96,7 +134,6 @@ def test_init_of_abstract_model():
 
 def test_field_redefining_raises_error():
     with pytest.raises(ModelDefinitionError):
-
         class WrongField(DateFieldsModel):  # pragma: no cover
             class Meta(ormar.ModelMeta):
                 tablename = "wrongs"
@@ -109,7 +146,6 @@ def test_field_redefining_raises_error():
 
 def test_model_subclassing_non_abstract_raises_error():
     with pytest.raises(ModelDefinitionError):
-
         class WrongField2(DateFieldsModelNoSubclass):  # pragma: no cover
             class Meta(ormar.ModelMeta):
                 tablename = "wrongs"
@@ -201,3 +237,21 @@ async def test_fields_inherited_from_mixin():
             assert sub3.updated_date is None
             assert sub3.category.created_by == "Sam"
             assert sub3.category.updated_by == cat.updated_by
+
+
+@pytest.mark.asyncio
+async def test_inheritance_with_relation():
+    async with db:
+        async with db.transaction(force_rollback=True):
+            sam = await Person(name='Sam').save()
+            joe = await Person(name='Joe').save()
+            await Truck(name='Shelby wanna be', max_capacity=1400, owner=sam, co_owner=joe).save()
+
+            shelby = await Truck.objects.select_related(['owner', 'co_owner']).get()
+            assert shelby.name == 'Shelby wanna be'
+            assert shelby.owner.name == 'Sam'
+            assert shelby.co_owner.name == 'Joe'
+
+            joe_check = await Person.objects.select_related('coowned_trucks').get(name='Joe')
+            assert joe_check.pk == joe.pk
+            assert joe_check.coowned_trucks[0] == shelby