From 1cfae33fb0dd627b8560aecb56de72ea60380ad2 Mon Sep 17 00:00:00 2001
From: Mihir Kandoi <kandoimihir@gmail.com>
Date: Fri, 19 Jun 2026 21:21:06 +0530
Subject: [PATCH] refactor(postgres): port transaction_base delete_events to
 the query builder

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
---
 erpnext/utilities/test_transaction_base.py | 77 ++++++++++++++++++++++
 erpnext/utilities/transaction_base.py      | 21 +++---
 2 files changed, 86 insertions(+), 12 deletions(-)
 create mode 100644 erpnext/utilities/test_transaction_base.py

diff --git a/erpnext/utilities/test_transaction_base.py b/erpnext/utilities/test_transaction_base.py
new file mode 100644
index 00000000000..6d297d02c38
--- /dev/null
+++ b/erpnext/utilities/test_transaction_base.py
@@ -0,0 +1,77 @@
+# Copyright (c) 2024, Frappe Technologies Pvt. Ltd. and Contributors
+# License: GNU General Public License v3. See license.txt
+
+import frappe
+from frappe.utils import now_datetime, random_string
+
+from erpnext.tests.utils import ERPNextTestSuite
+from erpnext.utilities.transaction_base import delete_events
+
+
+class TestDeleteEvents(ERPNextTestSuite):
+	def _make_event(self, reference_doctype, reference_docname):
+		# Insert a bare Event, then attach the Event Participants child row directly.
+		# reference_docname is a Dynamic Link that would otherwise be validated against a
+		# real target doc on save; db_insert keeps the test self-contained with arbitrary
+		# (random, guaranteed-unique) docnames while still populating exactly the columns
+		# delete_events joins/filters on (parent, reference_doctype, reference_docname).
+		event = frappe.get_doc(
+			{
+				"doctype": "Event",
+				"subject": "Test Event " + random_string(10),
+				"starts_on": now_datetime(),
+				"event_type": "Private",
+			}
+		).insert(ignore_permissions=True)
+
+		participant = frappe.new_doc("Event Participants")
+		participant.name = frappe.generate_hash(length=10)
+		participant.flags.name_set = True
+		participant.parent = event.name
+		participant.parenttype = "Event"
+		participant.parentfield = "event_participants"
+		participant.idx = 1
+		participant.reference_doctype = reference_doctype
+		participant.reference_docname = reference_docname
+		participant.db_insert()
+
+		return event.name
+
+	def test_delete_events_removes_matching_and_keeps_others(self):
+		# Two distinct, real reference_docnames so the filter has something to discriminate on.
+		match_name = "Match " + random_string(10)
+		other_name = "Other " + random_string(10)
+		event_match = self._make_event("Customer", match_name)
+		event_other = self._make_event("Customer", other_name)
+
+		# Sanity: both exist before deletion (otherwise the assertions below are tautological).
+		self.assertTrue(frappe.db.exists("Event", event_match))
+		self.assertTrue(frappe.db.exists("Event", event_other))
+
+		delete_events("Customer", match_name)
+
+		# Only the Event whose participant matches BOTH reference_doctype and
+		# reference_docname must be deleted.
+		self.assertFalse(frappe.db.exists("Event", event_match))
+		self.assertTrue(frappe.db.exists("Event", event_other))
+
+	def test_delete_events_no_match_is_noop(self):
+		# When nothing matches, no Event may be deleted.
+		event = self._make_event("Customer", "Present " + random_string(10))
+		self.assertTrue(frappe.db.exists("Event", event))
+
+		delete_events("Customer", "Absent " + random_string(10))
+
+		self.assertTrue(frappe.db.exists("Event", event))
+
+	def test_delete_events_distinguishes_reference_doctype(self):
+		# Same docname under two different reference_doctypes: only the queried doctype
+		# is deleted, proving both predicates are ANDed together.
+		shared_name = "Shared " + random_string(10)
+		event_customer = self._make_event("Customer", shared_name)
+		event_supplier = self._make_event("Supplier", shared_name)
+
+		delete_events("Customer", shared_name)
+
+		self.assertFalse(frappe.db.exists("Event", event_customer))
+		self.assertTrue(frappe.db.exists("Event", event_supplier))
diff --git a/erpnext/utilities/transaction_base.py b/erpnext/utilities/transaction_base.py
index 4b51bc5ecd3..bd7bbcdd34b 100644
--- a/erpnext/utilities/transaction_base.py
+++ b/erpnext/utilities/transaction_base.py
@@ -582,19 +582,16 @@ class TransactionBase(StatusUpdater):
 
 
 def delete_events(ref_type, ref_name):
+	event = frappe.qb.DocType("Event")
+	participant = frappe.qb.DocType("Event Participants")
 	events = (
-		frappe.db.sql_list(
-			""" SELECT
-			distinct `tabEvent`.name
-		from
-			`tabEvent`, `tabEvent Participants`
-		where
-			`tabEvent`.name = `tabEvent Participants`.parent
-			and `tabEvent Participants`.reference_doctype = %s
-			and `tabEvent Participants`.reference_docname = %s
-		""",
-			(ref_type, ref_name),
-		)
+		frappe.qb.from_(event)
+		.inner_join(participant)
+		.on(event.name == participant.parent)
+		.select(event.name)
+		.distinct()
+		.where((participant.reference_doctype == ref_type) & (participant.reference_docname == ref_name))
+		.run(pluck="name")
 		or []
 	)