Made join_table query optional based on item group filter
diff --git a/erpnext/stock/report/stock_balance/stock_balance.py b/erpnext/stock/report/stock_balance/stock_balance.py
index 365e52b..1203625 100644
--- a/erpnext/stock/report/stock_balance/stock_balance.py
+++ b/erpnext/stock/report/stock_balance/stock_balance.py
@@ -84,12 +84,16 @@
 
 def get_stock_ledger_entries(filters):
 	conditions = get_conditions(filters)
+	
+	join_table_query = ""
+	if filters.get("item_group"):
+		join_table_query = "inner join `tabItem` item on item.name = sle.item_code"
+	
 	return frappe.db.sql("""select sle.item_code, warehouse, sle.posting_date, sle.actual_qty, sle.valuation_rate,
 			sle.company, sle.voucher_type, sle.qty_after_transaction, sle.stock_value_difference
-		from `tabStock Ledger Entry` sle force index (posting_sort_index)
-		inner join `tabItem` item on item.name = sle.item_code
+		from `tabStock Ledger Entry` sle force index (posting_sort_index) %s
 		where sle.docstatus < 2 %s order by sle.posting_date, sle.posting_time, sle.name""" %
-		conditions, as_dict=1)
+		(join_table_query, conditions), as_dict=1)
 
 def get_item_warehouse_map(filters):
 	iwb_map = {}