Patch for default BOM
diff --git a/erpnext/patches.txt b/erpnext/patches.txt
index f5ae5b7..c483665 100644
--- a/erpnext/patches.txt
+++ b/erpnext/patches.txt
@@ -176,3 +176,4 @@
erpnext.patches.v5_1.sales_bom_rename
execute:frappe.rename_doc("DocType", "Salary Manager", "Process Payroll", force=True)
erpnext.patches.v5_1.rename_roles
+erpnext.patches.v5_1.default_bom
diff --git a/erpnext/patches/v5_1/default_bom.py b/erpnext/patches/v5_1/default_bom.py
new file mode 100644
index 0000000..6484edd
--- /dev/null
+++ b/erpnext/patches/v5_1/default_bom.py
@@ -0,0 +1,7 @@
+from __future__ import unicode_literals
+
+import frappe
+
+def execute():
+ frappe.db.sql("""Update `tabItem` as item set default_bom = NULL where
+ not exists(select name from `tabBOM` as bom where item.default_bom = bom.name and bom.docstatus =1 )""")
\ No newline at end of file