From 551e0dec26d4e25cb68b1e19ccf46a1bfb4d6088 Mon Sep 17 00:00:00 2001
From: Ivo Oskamp <ivooskamp@oskamp.info>
Date: Tue, 6 Jan 2026 11:29:00 +0100
Subject: [PATCH] Auto-commit local changes before build (2026-01-06 11:29:00)

---
 .last-branch                                  |  2 +-
 .../src/backend/app/main/routes_customers.py  |  3 ++
 .../src/backend/app/migrations.py             | 33 +++++++++++++++++++
 docs/changelog.md                             |  8 +++++
 4 files changed, 45 insertions(+), 1 deletion(-)

diff --git a/.last-branch b/.last-branch
index b69a15b..53aafa4 100644
--- a/.last-branch
+++ b/.last-branch
@@ -1 +1 @@
-v20260106-05-jobs-row-click-and-archive-button-move
+v20260106-06-customers-delete-fk-cascade-fix
diff --git a/containers/backupchecks/src/backend/app/main/routes_customers.py b/containers/backupchecks/src/backend/app/main/routes_customers.py
index 9e53b7d..f4348ae 100644
--- a/containers/backupchecks/src/backend/app/main/routes_customers.py
+++ b/containers/backupchecks/src/backend/app/main/routes_customers.py
@@ -100,6 +100,9 @@ def customers_delete(customer_id: int):
     customer = Customer.query.get_or_404(customer_id)
 
     try:
+        # Prevent FK violations on older schemas and keep jobs for historical reporting.
+        # Jobs are not deleted when removing a customer; they are simply unlinked.
+        Job.query.filter_by(customer_id=customer.id).update({"customer_id": None})
         db.session.delete(customer)
         db.session.commit()
         flash("Customer deleted.", "success")
diff --git a/containers/backupchecks/src/backend/app/migrations.py b/containers/backupchecks/src/backend/app/migrations.py
index 94f376f..5980336 100644
--- a/containers/backupchecks/src/backend/app/migrations.py
+++ b/containers/backupchecks/src/backend/app/migrations.py
@@ -1137,6 +1137,39 @@ def migrate_object_persistence_tables() -> None:
                 '''
             )
         )
+
+        # Ensure existing installations also have ON DELETE CASCADE on customer_objects.customer_id.
+        # Older schemas created the FK without cascade, which blocks deleting customers.
+        conn.execute(
+            text(
+                '''
+                DO $$
+                BEGIN
+                    IF EXISTS (
+                        SELECT 1
+                        FROM information_schema.table_constraints tc
+                        WHERE tc.table_name = 'customer_objects'
+                          AND tc.constraint_type = 'FOREIGN KEY'
+                          AND tc.constraint_name = 'customer_objects_customer_id_fkey'
+                    ) THEN
+                        ALTER TABLE customer_objects
+                            DROP CONSTRAINT customer_objects_customer_id_fkey;
+                    END IF;
+
+                    -- Recreate with cascade (idempotent via the drop above)
+                    ALTER TABLE customer_objects
+                        ADD CONSTRAINT customer_objects_customer_id_fkey
+                        FOREIGN KEY (customer_id)
+                        REFERENCES customers(id)
+                        ON DELETE CASCADE;
+                EXCEPTION
+                    WHEN duplicate_object THEN
+                        -- Constraint already exists with the correct name.
+                        NULL;
+                END $$;
+                '''
+            )
+        )
         conn.execute(
             text(
                 'CREATE INDEX IF NOT EXISTS idx_customer_objects_customer_name ON customer_objects (customer_id, object_name)'
diff --git a/docs/changelog.md b/docs/changelog.md
index dc1de2f..0ca8b57 100644
--- a/docs/changelog.md
+++ b/docs/changelog.md
@@ -38,6 +38,14 @@
 - Moved the Archive action from the Jobs table to the Job Details page.
 - Placed the Archive button next to the existing Delete job button for better consistency.
 
+---
+
+## v20260106-06-customers-delete-fk-cascade-fix
+
+- Fixed customer deletion failing with FK constraint errors caused by existing customer_objects rows.
+- Migration: enforced ON DELETE CASCADE on customer_objects.customer_id by recreating the FK constraint if needed (idempotent).
+- Customer delete flow: unlinks jobs (sets jobs.customer_id to NULL) before deleting the customer, so historical job/run data remains intact.
+
 ================================================================================================================================================
 ## v0.1.16
 
-- 
2.45.2