fix(postgres): fix v15 migration failures on Postgres (#51481)

* fix(postgres): avoid DISTINCT(...) in repost allowed types query

* fix(postgres): rewrite update pick list patch to avoid UPDATE JOIN

* chore: linting changes

---------

Co-authored-by: Matt Howard <[email protected]>
Co-authored-by: ruthra kumar <[email protected]>

Author: 3 people

erpnext/accounts/doctype/repost_accounting_ledger/repost_accounting_ledger.py

@@ -215,16 +215,22 @@ def start_repost(account_repost_doc=str) -> None:
 
 
 def get_allowed_types_from_settings(child_doc: bool = False):
-	repost_docs = [
-		x.document_type
-		for x in frappe.db.get_all(
-			"Repost Allowed Types", filters={"allowed": True}, fields=["distinct(document_type)"]
-		)
-	]
+	# Avoid DISTINCT(...) here: Frappe applies a default ORDER BY which breaks on Postgres
+	# when used with SELECT DISTINCT.
+	repost_docs = frappe.db.get_all(
+		"Repost Allowed Types",
+		filters={"allowed": True},
+		pluck="document_type",
+	)
+
+	# De-dupe while preserving order (first occurrence wins)
+	repost_docs = list(dict.fromkeys(repost_docs))
 	result = repost_docs
 
 	if repost_docs and child_doc:
 		result.extend(get_child_docs(repost_docs))
+		# Keep uniqueness after extending
+		result = list(dict.fromkeys(result))
 
 	return result
 
@@ -291,8 +297,11 @@ def get_repost_allowed_types(doctype, txt, searchfield, start, page_len, filters
 	if txt:
 		filters.update({"document_type": ("like", f"%{txt}%")})
 
-	if allowed_types := frappe.db.get_all(
-		"Repost Allowed Types", filters=filters, fields=["distinct(document_type)"], as_list=1
-	):
-		return allowed_types
-	return []
+	allowed_types = frappe.db.get_all(
+		"Repost Allowed Types",
+		filters=filters,
+		pluck="document_type",
+	)
+
+	allowed_types = list(dict.fromkeys(allowed_types))
+	return [[dt] for dt in allowed_types]

erpnext/patches/v15_0/update_pick_list_fields.py

@@ -8,12 +8,24 @@ def execute():
 
 
 def update_delivery_note():
-	DN = frappe.qb.DocType("Delivery Note")
-	DNI = frappe.qb.DocType("Delivery Note Item")
-
-	frappe.qb.update(DNI).join(DN).on(DN.name == DNI.parent).set(DNI.against_pick_list, DN.pick_list).where(
-		IfNull(DN.pick_list, "") != ""
-	).run()
+	# Postgres doesn't support UPDATE ... JOIN. Use UPDATE ... FROM instead.
+	frappe.db.multisql(
+		{
+			"mariadb": """
+				UPDATE `tabDelivery Note Item` dni
+				JOIN `tabDelivery Note` dn ON dn.`name` = dni.`parent`
+				SET dni.`against_pick_list` = dn.`pick_list`
+				WHERE COALESCE(dn.`pick_list`, '') <> ''
+			""",
+			"postgres": """
+				UPDATE "tabDelivery Note Item" dni
+				SET against_pick_list = dn.pick_list
+				FROM "tabDelivery Note" dn
+				WHERE dn.name = dni.parent
+				  AND COALESCE(dn.pick_list, '') <> ''
+			""",
+		}
+	)
 
 
 def update_pick_list_items():