fix: add cascade_backrefs=False for all ORM relationships

prep for eventual SQLAlchemy 2.x

src/wuttjamaican/db/model/batch.py

@@ -182,7 +182,6 @@ class BatchMixin:
 
        Reference to the :class:`~wuttjamaican.db.model.auth.User` who
        executed the batch.
-
     """
 
     @declared_attr
@@ -231,7 +230,8 @@ class BatchMixin:
         return orm.relationship(
             User,
             primaryjoin=lambda: User.uuid == cls.created_by_uuid,
-            foreign_keys=lambda: [cls.created_by_uuid])
+            foreign_keys=lambda: [cls.created_by_uuid],
+            cascade_backrefs=False)
 
 
     executed = sa.Column(sa.DateTime(timezone=True), nullable=True)
@@ -242,7 +242,8 @@ class BatchMixin:
         return orm.relationship(
             User,
             primaryjoin=lambda: User.uuid == cls.executed_by_uuid,
-            foreign_keys=lambda: [cls.executed_by_uuid])
+            foreign_keys=lambda: [cls.executed_by_uuid],
+            cascade_backrefs=False)
 
     def __repr__(self):
         cls = self.__class__.__name__
@@ -404,12 +405,14 @@ class BatchRowMixin:
             order_by=lambda: row_class.sequence,
             collection_class=ordering_list('sequence', count_from=1),
             cascade='all, delete-orphan',
+            cascade_backrefs=False,
             back_populates='batch')
 
         # now, here's the `BatchRow.batch`
         return orm.relationship(
             batch_class,
-            back_populates='rows')
+            back_populates='rows',
+            cascade_backrefs=False)
 
     sequence = sa.Column(sa.Integer(), nullable=False)
 

src/wuttjamaican/db/model/upgrades.py

@@ -52,6 +52,7 @@ class Upgrade(Base):
     created_by = orm.relationship(
         'User',
         foreign_keys=[created_by_uuid],
+        cascade_backrefs=False,
         doc="""
         :class:`~wuttjamaican.db.model.auth.User` who created the
         upgrade record.
@@ -82,6 +83,7 @@ class Upgrade(Base):
     executed_by = orm.relationship(
         'User',
         foreign_keys=[executed_by_uuid],
+        cascade_backrefs=False,
         doc="""
         :class:`~wuttjamaican.db.model.auth.User` who executed the
         upgrade.