diff --git a/erpnext/patches.txt b/erpnext/patches.txt
index 658b7e7..eb29528 100644
--- a/erpnext/patches.txt
+++ b/erpnext/patches.txt
@@ -546,4 +546,5 @@
 erpnext.patches.v10_0.update_status_in_purchase_receipt
 erpnext.patches.v11_0.inter_state_field_for_gst
 erpnext.patches.v11_0.rename_members_with_naming_series #04-06-2018
-erpnext.patches.v11_0.set_update_field_and_value_in_workflow_state
\ No newline at end of file
+erpnext.patches.v11_0.set_update_field_and_value_in_workflow_state
+erpnext.patches.v11_0.update_total_qty_field
diff --git a/erpnext/patches/v11_0/update_total_qty_field.py b/erpnext/patches/v11_0/update_total_qty_field.py
index e618593..6f78d8a 100644
--- a/erpnext/patches/v11_0/update_total_qty_field.py
+++ b/erpnext/patches/v11_0/update_total_qty_field.py
@@ -9,19 +9,26 @@
 	frappe.reload_doc('stock', 'doctype', 'purchase_receipt')
 	frappe.reload_doc('accounts', 'doctype', 'sales_invoice')
 	frappe.reload_doc('accounts', 'doctype', 'purchase_invoice')
-
+ 
 	doctypes = ["Sales Order", "Sales Invoice", "Delivery Note",\
 		"Purchase Order", "Purchase Invoice", "Purchase Receipt", "Quotation", "Supplier Quotation"]
 
 	for doctype in doctypes:
+		total_qty =	frappe.db.sql('''
+			SELECT
+				parent, SUM(qty) as qty
+			FROM
+				`tab%s Item`
+			GROUP BY parent
+		''' % (doctype), as_dict = True)
+
+		when_then = []
+		for d in total_qty:
+			when_then.append("""
+				when dt.name = '{0}' then {1}
+			""".format(frappe.db.escape(d.get("parent")), d.get("qty")))
+
 		frappe.db.sql('''
 			UPDATE
-				`tab%s` dt SET dt.total_qty =
-			(
-				SELECT SUM(dt_item.qty)
-				FROM
-					`tab%s Item` dt_item
-				WHERE
-					dt_item.parent=dt.name
-			)
-		''' % (doctype, doctype))
+				`tab%s` dt SET dt.total_qty = CASE %s END
+		''' % (doctype, " ".join(when_then)))
\ No newline at end of file