♻️ Refactor models to use cascade delete relationships (#1276)

Author: alejsdev

backend/app/alembic/versions/1a31ce608336_add_cascade_delete_relationships.py

@@ -0,0 +1,37 @@
+"""Add cascade delete relationships
+
+Revision ID: 1a31ce608336
+Revises: d98dd8ec85a3
+Create Date: 2024-07-31 22:24:34.447891
+
+"""
+from alembic import op
+import sqlalchemy as sa
+import sqlmodel.sql.sqltypes
+
+
+# revision identifiers, used by Alembic.
+revision = '1a31ce608336'
+down_revision = 'd98dd8ec85a3'
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.alter_column('item', 'owner_id',
+               existing_type=sa.UUID(),
+               nullable=False)
+    op.drop_constraint('item_owner_id_fkey', 'item', type_='foreignkey')
+    op.create_foreign_key(None, 'item', 'user', ['owner_id'], ['id'], ondelete='CASCADE')
+    # ### end Alembic commands ###
+
+
+def downgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.drop_constraint(None, 'item', type_='foreignkey')
+    op.create_foreign_key('item_owner_id_fkey', 'item', 'user', ['owner_id'], ['id'])
+    op.alter_column('item', 'owner_id',
+               existing_type=sa.UUID(),
+               nullable=True)
+    # ### end Alembic commands ###

backend/app/models.py

@@ -43,7 +43,7 @@ class UpdatePassword(SQLModel):
 class User(UserBase, table=True):
     id: uuid.UUID = Field(default_factory=uuid.uuid4, primary_key=True)
     hashed_password: str
-    items: list["Item"] = Relationship(back_populates="owner")
+    items: list["Item"] = Relationship(back_populates="owner", cascade_delete=True)
 
 
 # Properties to return via API, id is always required
@@ -76,7 +76,9 @@ class ItemUpdate(ItemBase):
 class Item(ItemBase, table=True):
     id: uuid.UUID = Field(default_factory=uuid.uuid4, primary_key=True)
     title: str = Field(max_length=255)
-    owner_id: uuid.UUID = Field(foreign_key="user.id", nullable=False)
+    owner_id: uuid.UUID = Field(
+        foreign_key="user.id", nullable=False, ondelete="CASCADE"
+    )
     owner: User | None = Relationship(back_populates="items")