fix(stock): make Available Batch report GROUP BY Postgres-valid

Both get_batchwise_data_from_stock_ledger and
get_batchwise_data_from_serial_batch_bundle select Batch columns
(expiry_date, and item_name when show_item_name is set) while grouping
only by Stock Ledger Entry columns. MariaDB arbitrary-picks the Batch
columns; Postgres rejects the query with "column ... must appear in the
GROUP BY clause".

Add the Batch PK (batch.name) to both GROUP BYs. batch.name is 1:1 with
the grouped batch_no (the join condition), so groups are unchanged and the
result is identical on MariaDB.

The serial-batch-bundle query additionally grouped by ch_table.warehouse
while selecting table.warehouse; group by the selected (SLE) warehouse so
the grouped and selected columns match (also required by Postgres).

Adds a test (no test file existed) that receives batch stock and asserts
the report lists it with the correct balance, exercising the GROUP BY on
both engines (with show_item_name set to force the extra Batch column).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

erpnext/stock/report/available_batch_report/available_batch_report.py

@@ -106,7 +106,9 @@ def get_batchwise_data_from_stock_ledger(filters):
 			Sum(table.actual_qty).as_("balance_qty"),
 		)
 		.where(table.is_cancelled == 0)
-		.groupby(table.batch_no, table.item_code, table.warehouse)
+		# batch.expiry_date comes from the Batch table; postgres requires its PK in the GROUP BY for
+		# it to be selectable. batch.name is 1:1 with the grouped batch_no, so groups are unchanged.
+		.groupby(table.batch_no, table.item_code, table.warehouse, batch.name)
 	)
 
 	query = get_query_based_on_filters(query, batch, table, filters)
@@ -137,7 +139,10 @@ def get_batchwise_data_from_serial_batch_bundle(batchwise_data, filters):
 			Sum(ch_table.qty).as_("balance_qty"),
 		)
 		.where((table.is_cancelled == 0) & (table.docstatus == 1))
-		.groupby(ch_table.batch_no, table.item_code, ch_table.warehouse)
+		# Group by the same (SLE) warehouse that is selected -- the original grouped by
+		# ch_table.warehouse while selecting table.warehouse, which postgres rejects. Also group by
+		# the Batch PK so batch.expiry_date is selectable (1:1 with the grouped batch_no).
+		.groupby(ch_table.batch_no, table.item_code, table.warehouse, batch.name)
 	)
 
 	query = get_query_based_on_filters(query, batch, table, filters)

erpnext/stock/report/available_batch_report/test_available_batch_report.py

@@ -0,0 +1,49 @@
+# Copyright (c) 2024, Frappe Technologies Pvt. Ltd. and contributors
+# For license information, please see license.txt
+
+import frappe
+from frappe.utils import today
+
+from erpnext.tests.utils import ERPNextTestSuite
+
+
+class TestAvailableBatchReport(ERPNextTestSuite):
+	@staticmethod
+	def _cancel_and_delete_stock_entry(name):
+		if not frappe.db.exists("Stock Entry", name):
+			return
+		doc = frappe.get_doc("Stock Entry", name)
+		if doc.docstatus == 1:
+			doc.cancel()
+		frappe.delete_doc("Stock Entry", name, force=1)
+
+	def test_report_runs_and_lists_batch_qty(self):
+		# The report selects Batch columns (expiry_date, and item_name when show_item_name is set)
+		# while grouping by SLE columns; the Batch PK must be in the GROUP BY for the report to run
+		# on Postgres. show_item_name=1 forces the extra Batch column to be selected.
+		from erpnext.stock.doctype.item.test_item import make_item
+		from erpnext.stock.doctype.serial_and_batch_bundle.test_serial_and_batch_bundle import (
+			get_batch_from_bundle,
+		)
+		from erpnext.stock.doctype.stock_entry.stock_entry_utils import make_stock_entry
+		from erpnext.stock.report.available_batch_report.available_batch_report import execute
+
+		item = make_item(
+			"_Test Available Batch Report Item",
+			{"has_batch_no": 1, "create_new_batch": 1, "is_stock_item": 1},
+		).name
+		se = make_stock_entry(
+			item_code=item, target="_Test Warehouse - _TC", qty=7, basic_rate=10, purpose="Material Receipt"
+		)
+		# make_item is idempotent (returns the existing item), but each receipt stacks a new batch,
+		# so cancel+delete the stock entry to keep repeated runs clean.
+		self.addCleanup(self._cancel_and_delete_stock_entry, se.name)
+		batch_no = get_batch_from_bundle(se.items[0].serial_and_batch_bundle)
+
+		filters = frappe._dict(to_date=today(), item_code=item, show_item_name=1)
+		columns, data = execute(filters)
+
+		self.assertTrue(columns)
+		row = next((d for d in data if d.batch_no == batch_no), None)
+		self.assertIsNotNone(row)
+		self.assertEqual(row.balance_qty, 7)