patch: delete all orphaned tables docs (#26863)

erpnext/patches.txt

@@ -294,6 +294,7 @@ erpnext.patches.v13_0.update_level_in_bom #1234sswef
 erpnext.patches.v13_0.add_missing_fg_item_for_stock_entry
 erpnext.patches.v13_0.update_subscription_status_in_memberships
 erpnext.patches.v13_0.update_amt_in_work_order_required_items
+erpnext.patches.v13_0.delete_orphaned_tables
 erpnext.patches.v13_0.update_export_type_for_gst
 erpnext.patches.v13_0.update_tds_check_field #3
 erpnext.patches.v13_0.update_recipient_email_digest

erpnext/patches/v13_0/delete_orphaned_tables.py

@@ -0,0 +1,69 @@
+# Copyright (c) 2019, Frappe and Contributors
+# License: GNU General Public License v3. See license.txt
+
+from __future__ import unicode_literals
+
+import frappe
+from frappe.utils import getdate
+
+def execute():
+    frappe.reload_doc('setup', 'doctype', 'transaction_deletion_record')
+
+    if has_deleted_company_transactions():
+        child_doctypes = get_child_doctypes_whose_parent_doctypes_were_affected()
+
+        for doctype in child_doctypes:
+            docs = frappe.get_all(doctype, fields=['name', 'parent', 'parenttype', 'creation'])
+
+            for doc in docs:
+                if not frappe.db.exists(doc['parenttype'], doc['parent']):
+                    frappe.db.delete(doctype, {'name': doc['name']})
+
+                elif check_for_new_doc_with_same_name_as_deleted_parent(doc):
+                    frappe.db.delete(doctype, {'name': doc['name']})
+
+def has_deleted_company_transactions():
+    return frappe.get_all('Transaction Deletion Record')
+
+def get_child_doctypes_whose_parent_doctypes_were_affected():
+    parent_doctypes = get_affected_doctypes()
+    child_doctypes = frappe.get_all(
+        'DocField', 
+        filters={
+            'fieldtype': 'Table', 
+            'parent':['in', parent_doctypes]
+        }, pluck='options')
+
+    return child_doctypes
+
+def get_affected_doctypes():
+    affected_doctypes = []
+    tdr_docs = frappe.get_all('Transaction Deletion Record', pluck="name")
+    
+    for tdr in tdr_docs:
+        tdr_doc = frappe.get_doc("Transaction Deletion Record", tdr)
+
+        for doctype in tdr_doc.doctypes:
+            if is_not_child_table(doctype.doctype_name):
+                affected_doctypes.append(doctype.doctype_name)
+
+    affected_doctypes = remove_duplicate_items(affected_doctypes)
+    return affected_doctypes
+
+def is_not_child_table(doctype):
+    return not bool(frappe.get_value('DocType', doctype, 'istable'))
+
+def remove_duplicate_items(affected_doctypes):
+    return list(set(affected_doctypes))
+
+def check_for_new_doc_with_same_name_as_deleted_parent(doc):
+    """
+        Compares creation times of parent and child docs.
+        Since Transaction Deletion Record resets the naming series after deletion,
+        it allows the creation of new docs with the same names as the deleted ones.
+    """
+
+    parent_creation_time = frappe.db.get_value(doc['parenttype'], doc['parent'], 'creation')
+    child_creation_time = doc['creation']
+
+    return getdate(parent_creation_time) > getdate(child_creation_time)