fix(relations): allow deleting transaction when relation exists

7project/backend/alembic/versions/2025_10_30_1342-59cebf320c4a_cascade_categories.py

@@ -0,0 +1,46 @@
+"""Cascade categories
+
+Revision ID: 59cebf320c4a
+Revises: 46b9e702e83f
+Create Date: 2025-10-30 13:42:44.555284
+
+"""
+from typing import Sequence, Union
+
+from alembic import op
+import sqlalchemy as sa
+from sqlalchemy.dialects import mysql
+
+# revision identifiers, used by Alembic.
+revision: str = '59cebf320c4a'
+down_revision: Union[str, Sequence[str], None] = '46b9e702e83f'
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    """Upgrade schema."""
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.add_column('category_transaction', sa.Column('category_id', sa.Integer(), nullable=False))
+    op.add_column('category_transaction', sa.Column('transaction_id', sa.Integer(), nullable=False))
+    op.drop_constraint(op.f('category_transaction_ibfk_2'), 'category_transaction', type_='foreignkey')
+    op.drop_constraint(op.f('category_transaction_ibfk_1'), 'category_transaction', type_='foreignkey')
+    op.create_foreign_key(None, 'category_transaction', 'transaction', ['transaction_id'], ['id'], ondelete='CASCADE')
+    op.create_foreign_key(None, 'category_transaction', 'categories', ['category_id'], ['id'], ondelete='CASCADE')
+    op.drop_column('category_transaction', 'id_category')
+    op.drop_column('category_transaction', 'id_transaction')
+    # ### end Alembic commands ###
+
+
+def downgrade() -> None:
+    """Downgrade schema."""
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.add_column('category_transaction', sa.Column('id_transaction', mysql.INTEGER(display_width=11), autoincrement=False, nullable=True))
+    op.add_column('category_transaction', sa.Column('id_category', mysql.INTEGER(display_width=11), autoincrement=False, nullable=True))
+    op.drop_constraint(None, 'category_transaction', type_='foreignkey')
+    op.drop_constraint(None, 'category_transaction', type_='foreignkey')
+    op.create_foreign_key(op.f('category_transaction_ibfk_1'), 'category_transaction', 'categories', ['id_category'], ['id'])
+    op.create_foreign_key(op.f('category_transaction_ibfk_2'), 'category_transaction', 'transaction', ['id_transaction'], ['id'])
+    op.drop_column('category_transaction', 'transaction_id')
+    op.drop_column('category_transaction', 'category_id')
+    # ### end Alembic commands ###

7project/backend/app/models/categories.py

@@ -7,8 +7,8 @@ from app.core.base import Base
 association_table = Table(
     "category_transaction",
     Base.metadata,
-    Column("id_category", Integer, ForeignKey("categories.id")),
+    Column("category_id", Integer, ForeignKey("categories.id", ondelete="CASCADE"), primary_key=True),
-    Column("id_transaction", Integer, ForeignKey("transaction.id"))
+    Column("transaction_id", Integer, ForeignKey("transaction.id", ondelete="CASCADE"), primary_key=True)
 )
 
 

7project/backend/app/models/transaction.py

@@ -21,4 +21,4 @@ class Transaction(Base):
 
     # Relationship
     user = relationship("User", back_populates="transactions")
-    categories = relationship("Category", secondary=association_table, back_populates="transactions")
+    categories = relationship("Category", secondary=association_table, back_populates="transactions", passive_deletes=True)