diff --git a/erpnext/stock/doctype/purchase_receipt/purchase_receipt.py b/erpnext/stock/doctype/purchase_receipt/purchase_receipt.py
index 0905b5b3b06..a99c536dd5b 100644
--- a/erpnext/stock/doctype/purchase_receipt/purchase_receipt.py
+++ b/erpnext/stock/doctype/purchase_receipt/purchase_receipt.py
@@ -339,14 +339,17 @@ class PurchaseReceipt(BuyingController):
 					frappe.throw(_(msg))
 
 	def get_already_received_qty(self, po, po_detail):
-		qty = frappe.db.sql(
-			"""select sum(qty) from `tabPurchase Receipt Item`
-			where purchase_order_item = %s and docstatus = 1
-			and purchase_order=%s
-			and parent != %s""",
-			(po_detail, po, self.name),
+		qty = frappe.get_all(
+			"Purchase Receipt Item",
+			filters={
+				"purchase_order_item": po_detail,
+				"docstatus": 1,
+				"purchase_order": po,
+				"parent": ["!=", self.name],
+			},
+			fields=[{"SUM": "qty", "as": "qty"}],
 		)
-		return qty and flt(qty[0][0]) or 0.0
+		return flt(qty[0].qty) if qty and qty[0].qty else 0.0
 
 	def get_po_qty_and_warehouse(self, po_detail):
 		po_qty, po_warehouse = frappe.db.get_value("Purchase Order Item", po_detail, ["qty", "warehouse"])
@@ -415,25 +418,27 @@ class PurchaseReceipt(BuyingController):
 					)
 
 	def check_next_docstatus(self):
-		submit_rv = frappe.db.sql(
-			"""select t1.name
-			from `tabPurchase Invoice` t1,`tabPurchase Invoice Item` t2
-			where t1.name = t2.parent and t2.purchase_receipt = %s and t1.docstatus = 1""",
-			(self.name),
+		submit_rv = frappe.get_all(
+			"Purchase Invoice Item",
+			filters={"purchase_receipt": self.name, "docstatus": 1},
+			fields=["parent"],
+			as_list=True,
+			limit=1,
 		)
 		if submit_rv:
-			frappe.throw(_("Purchase Invoice {0} is already submitted").format(self.submit_rv[0][0]))
+			frappe.throw(_("Purchase Invoice {0} is already submitted").format(submit_rv[0][0]))
 
 	def on_cancel(self):
 		super().on_cancel()
 
 		self.check_for_on_hold_or_closed_status("Purchase Order", "purchase_order")
 		# Check if Purchase Invoice has been submitted against current Purchase Order
-		submitted = frappe.db.sql(
-			"""select t1.name
-			from `tabPurchase Invoice` t1,`tabPurchase Invoice Item` t2
-			where t1.name = t2.parent and t2.purchase_receipt = %s and t1.docstatus = 1""",
-			self.name,
+		submitted = frappe.get_all(
+			"Purchase Invoice Item",
+			filters={"purchase_receipt": self.name, "docstatus": 1},
+			fields=["parent"],
+			as_list=True,
+			limit=1,
 		)
 		if submitted:
 			frappe.throw(_("Purchase Invoice {0} is already submitted").format(submitted[0][0]))
diff --git a/erpnext/stock/doctype/purchase_receipt/test_purchase_receipt.py b/erpnext/stock/doctype/purchase_receipt/test_purchase_receipt.py
index 0393e7ae037..68c360f9396 100644
--- a/erpnext/stock/doctype/purchase_receipt/test_purchase_receipt.py
+++ b/erpnext/stock/doctype/purchase_receipt/test_purchase_receipt.py
@@ -6011,6 +6011,35 @@ class TestPurchaseReceipt(ERPNextTestSuite):
 		srbnb_credit = sum(flt(row.credit) for row in gl_entries if row.account == srbnb_account)
 		self.assertAlmostEqual(srbnb_credit, pi_base_net_amount, places=2)
 
+	def test_get_already_received_qty(self):
+		"""get_already_received_qty sums prior submitted PR Item qty against the same PO line,
+		excluding the current PR — covers the converted SUM with `parent != self.name`."""
+		from erpnext.buying.doctype.purchase_order.test_purchase_order import (
+			create_purchase_order,
+			make_pr_against_po,
+		)
+
+		po = create_purchase_order(qty=10)
+		po_detail = po.items[0].name
+
+		make_pr_against_po(po.name, 4)  # PR1 receives 4
+		pr2 = make_pr_against_po(po.name, 2)  # PR2 receives 2
+
+		# already received against this PO line, excluding pr2 itself, is pr1's 4
+		self.assertEqual(pr2.get_already_received_qty(po.name, po_detail), 4.0)
+
+	def test_check_next_docstatus_blocks_with_submitted_invoice(self):
+		"""check_next_docstatus must flag a submitted Purchase Invoice drawn from the receipt —
+		covers the converted child-table get_all (Purchase Invoice Item, docstatus=1)."""
+		pr = make_purchase_receipt()
+		pi = make_purchase_invoice(pr.name)
+		pi.insert()
+		pi.submit()
+
+		with self.assertRaises(frappe.ValidationError) as cm:
+			pr.check_next_docstatus()
+		self.assertIn("is already submitted", str(cm.exception))
+
 
 def create_asset_category_for_pr_test():
 	category_name = "Test Asset Category for PR"