diff --git a/erpnext/controllers/selling_controller.py b/erpnext/controllers/selling_controller.py
index 5be5d5dfdff..195aad6d74f 100644
--- a/erpnext/controllers/selling_controller.py
+++ b/erpnext/controllers/selling_controller.py
@@ -4,6 +4,7 @@
 
 import frappe
 from frappe import _, bold, throw
+from frappe.query_builder.functions import Sum
 from frappe.utils import cint, flt, get_link_to_form, nowtime
 
 from erpnext.accounts.party import render_address
@@ -439,22 +440,34 @@ class SellingController(StockController):
 			product_bundle_items[item_code] = item_code in items_with_product_bundle
 
 	def get_already_delivered_qty(self, current_docname, so, so_detail):
-		delivered_via_dn = frappe.db.sql(
-			"""select sum(qty) from `tabDelivery Note Item`
-			where so_detail = %s and docstatus = 1
-			and against_sales_order = %s
-			and parent != %s""",
-			(so_detail, so, current_docname),
+		dn_item = frappe.qb.DocType("Delivery Note Item")
+		delivered_via_dn = (
+			frappe.qb.from_(dn_item)
+			.select(Sum(dn_item.qty))
+			.where(
+				(dn_item.so_detail == so_detail)
+				& (dn_item.docstatus == 1)
+				& (dn_item.against_sales_order == so)
+				& (dn_item.parent != current_docname)
+			)
+			.run()
 		)
 
-		delivered_via_si = frappe.db.sql(
-			"""select sum(si_item.qty)
-			from `tabSales Invoice Item` si_item, `tabSales Invoice` si
-			where si_item.parent = si.name and si.update_stock = 1
-			and si_item.so_detail = %s and si.docstatus = 1
-			and si_item.sales_order = %s
-			and si.name != %s""",
-			(so_detail, so, current_docname),
+		si = frappe.qb.DocType("Sales Invoice")
+		si_item = frappe.qb.DocType("Sales Invoice Item")
+		delivered_via_si = (
+			frappe.qb.from_(si_item)
+			.inner_join(si)
+			.on(si_item.parent == si.name)
+			.select(Sum(si_item.qty))
+			.where(
+				(si.update_stock == 1)
+				& (si_item.so_detail == so_detail)
+				& (si.docstatus == 1)
+				& (si_item.sales_order == so)
+				& (si.name != current_docname)
+			)
+			.run()
 		)
 
 		total_delivered_qty = (flt(delivered_via_dn[0][0]) if delivered_via_dn else 0) + (
@@ -464,14 +477,11 @@ class SellingController(StockController):
 		return total_delivered_qty
 
 	def get_so_qty_and_warehouse(self, so_detail):
-		so_item = frappe.db.sql(
-			"""select qty, warehouse from `tabSales Order Item`
-			where name = %s and docstatus = 1""",
-			so_detail,
-			as_dict=1,
+		so_item = frappe.db.get_value(
+			"Sales Order Item", {"name": so_detail, "docstatus": 1}, ["qty", "warehouse"], as_dict=True
 		)
-		so_qty = so_item and flt(so_item[0]["qty"]) or 0.0
-		so_warehouse = so_item and so_item[0]["warehouse"] or ""
+		so_qty = flt(so_item.qty) if so_item else 0.0
+		so_warehouse = (so_item.warehouse if so_item else "") or ""
 		return so_qty, so_warehouse
 
 	def check_sales_order_on_hold_or_close(self, ref_fieldname):
diff --git a/erpnext/controllers/tests/test_selling_controller.py b/erpnext/controllers/tests/test_selling_controller.py
new file mode 100644
index 00000000000..16002caaed2
--- /dev/null
+++ b/erpnext/controllers/tests/test_selling_controller.py
@@ -0,0 +1,39 @@
+# Copyright (c) 2025, Frappe Technologies Pvt. Ltd. and Contributors
+# See license.txt
+
+import frappe
+
+from erpnext.tests.utils import ERPNextTestSuite
+
+
+class TestSellingControllerConversions(ERPNextTestSuite):
+	@staticmethod
+	def _cancel_and_delete(doctype, name):
+		if not frappe.db.exists(doctype, name):
+			return
+		doc = frappe.get_doc(doctype, name)
+		if doc.docstatus == 1:
+			doc.cancel()
+		frappe.delete_doc(doctype, name, force=1)
+
+	def test_partial_delivery_updates_sales_order_status(self):
+		# Submitting a Delivery Note against a Sales Order calls
+		# SellingController.get_already_delivered_qty / get_so_qty_and_warehouse and StatusUpdater
+		# (per_delivered via coalesce(sum(...))) -- all converted to query builder / ORM here.
+		from erpnext.selling.doctype.sales_order.mapper import make_delivery_note
+		from erpnext.selling.doctype.sales_order.test_sales_order import make_sales_order
+		from erpnext.stock.doctype.stock_entry.stock_entry_utils import make_stock_entry
+
+		se = make_stock_entry(item_code="_Test Item", target="_Test Warehouse - _TC", qty=20, basic_rate=100)
+		self.addCleanup(self._cancel_and_delete, "Stock Entry", se.name)
+
+		so = make_sales_order(qty=10)
+
+		dn = make_delivery_note(so.name)
+		dn.items[0].qty = 4
+		dn.insert()
+		dn.submit()
+		self.addCleanup(self._cancel_and_delete, "Delivery Note", dn.name)
+
+		so.reload()
+		self.assertEqual(so.per_delivered, 40.0)