fix(buying): keep Procurement Tracker one row per (PO, material_request_item)

The Postgres-portability change added the Purchase Order Item PK (child.name) to
get_po_entries' GROUP BY. material_request_item is blank for PO lines not sourced
from a Material Request, so a multi-line PO previously collapsed to ONE row per
(PO, blank) on MariaDB but now produced one row PER LINE — changing the MariaDB
row count (and the add_total_row totals).

Group only by (PO, material_request_item) — the pre-effort key — and Max()-
aggregate the other selected columns so the query stays valid on Postgres while
restoring the prior one-row-per-group MariaDB output (per-column arbitrary→
deterministic, row count preserved). Add a regression test with a two-line PO
that fails on the multi-column GROUP BY (2 rows) and passes after (1 row), on
both MariaDB and Postgres.

erpnext/buying/report/procurement_tracker/procurement_tracker.py

@@ -4,6 +4,7 @@
 
 import frappe
 from frappe import _
+from frappe.query_builder.functions import Max
 from frappe.utils import flt
 
 
@@ -282,32 +283,34 @@ def get_po_entries(filters):
 		frappe.qb.from_(parent)
 		.from_(child)
 		.select(
-			child.name,
-			child.parent,
-			child.cost_center,
-			child.project,
-			child.warehouse,
-			child.material_request,
+			Max(child.name).as_("name"),
+			Max(child.parent).as_("parent"),
+			Max(child.cost_center).as_("cost_center"),
+			Max(child.project).as_("project"),
+			Max(child.warehouse).as_("warehouse"),
+			Max(child.material_request).as_("material_request"),
 			child.material_request_item,
-			child.item_code,
-			child.stock_uom,
-			child.qty,
-			child.amount,
-			child.base_amount,
-			child.schedule_date,
-			parent.transaction_date,
-			parent.supplier,
-			parent.status,
-			parent.owner,
+			Max(child.item_code).as_("item_code"),
+			Max(child.stock_uom).as_("stock_uom"),
+			Max(child.qty).as_("qty"),
+			Max(child.amount).as_("amount"),
+			Max(child.base_amount).as_("base_amount"),
+			Max(child.schedule_date).as_("schedule_date"),
+			Max(parent.transaction_date).as_("transaction_date"),
+			Max(parent.supplier).as_("supplier"),
+			Max(parent.status).as_("status"),
+			Max(parent.owner).as_("owner"),
 		)
 		.where(
 			(parent.docstatus == 1)
 			& (parent.name == child.parent)
 			& (parent.status.notin(("Closed", "Completed", "Cancelled")))
 		)
-		# This is one row per PO item; the selected child.* columns are only functionally dependent
-		# on the child PK, which postgres requires in the GROUP BY (MariaDB allows omitting it).
-		.groupby(parent.name, child.material_request_item, child.name)
+		# Group only by the PO and material_request_item (the pre-effort key) and aggregate the rest
+		# with Max(): postgres requires every non-grouped column to be aggregated, and this keeps one
+		# row per (PO, material_request_item) — matching the prior MariaDB row count. Adding the PO
+		# Item PK to the GROUP BY would split a multi-line PO into one row per line.
+		.groupby(parent.name, child.material_request_item)
 	)
 	query = apply_filters_on_query(filters, parent, child, query)
 

erpnext/buying/report/procurement_tracker/test_procurement_tracker.py

@@ -2,14 +2,16 @@
 # For license information, please see license.txt
 
 
+from frappe.utils import add_days, nowdate
+
 from erpnext.tests.utils import ERPNextTestSuite
 
 
 class TestProcurementTracker(ERPNextTestSuite):
 	def test_report_executes_and_lists_po(self):
-		# get_po_entries groups by (Purchase Order, material_request_item, Purchase Order Item)
-		# while selecting other child columns; this exercises that GROUP BY so the report stays
-		# valid on Postgres (which rejects selecting non-grouped columns).
+		# get_po_entries groups by (Purchase Order, material_request_item) and Max()-aggregates the
+		# other child columns; this exercises that GROUP BY so the report stays valid on Postgres
+		# (which rejects selecting non-grouped columns).
 		from erpnext.buying.doctype.purchase_order.test_purchase_order import create_purchase_order
 		from erpnext.buying.report.procurement_tracker.procurement_tracker import execute
 
@@ -19,3 +21,32 @@ class TestProcurementTracker(ERPNextTestSuite):
 
 		self.assertTrue(columns)
 		self.assertIn(po.name, {row.get("purchase_order") for row in data})
+
+	def test_multi_line_po_stays_one_row(self):
+		# A PO can carry several lines that share the same (blank) material_request_item. get_po_entries
+		# groups by (Purchase Order, material_request_item) and Max()-aggregates the rest, so such a PO
+		# yields ONE row — matching the pre-effort MariaDB output. Adding the Purchase Order Item PK to
+		# the GROUP BY (the regression) splits it into one row per line, changing the MariaDB row count.
+		from erpnext.buying.doctype.purchase_order.test_purchase_order import create_purchase_order
+		from erpnext.buying.report.procurement_tracker.procurement_tracker import execute
+		from erpnext.stock.doctype.item.test_item import make_item
+
+		second_item = make_item("_Test Procurement Tracker Item", {"is_stock_item": 1}).name
+		po = create_purchase_order(company="_Test Company", do_not_submit=True)
+		po.append(
+			"items",
+			{
+				"item_code": second_item,
+				"warehouse": "_Test Warehouse - _TC",
+				"qty": 5,
+				"rate": 100,
+				"schedule_date": add_days(nowdate(), 1),
+			},
+		)
+		po.save()
+		po.submit()
+
+		columns, data = execute({"company": "_Test Company"})
+
+		po_rows = [row for row in data if row.get("purchase_order") == po.name]
+		self.assertEqual(len(po_rows), 1)