fix(party import): match existing contacts and addresses case-insensitively on every database

erpnext/utilities/party_import_provider.py

@@ -8,6 +8,8 @@ import frappe
 from frappe import _
 from frappe.core.doctype.data_import.import_provider import ImportProvider
 from frappe.core.doctype.data_import.importer import INSERT, UPDATE
+from frappe.query_builder.functions import Lower
+from frappe.utils import cstr
 
 from erpnext.selling.doctype.customer.mapper import parse_full_name
 
@@ -164,15 +166,26 @@ class PartyImportProvider(ImportProvider):
 
 
 def _find_linked(doctype: str, link_doctype: str, link_name: str, filters: dict) -> str | None:
-	"""Name of a ``doctype`` record linked to the party that matches ``filters``."""
-	return frappe.db.get_value(
-		doctype,
-		[
-			["Dynamic Link", "link_doctype", "=", link_doctype],
-			["Dynamic Link", "link_name", "=", link_name],
-			*[[field, "=", value] for field, value in filters.items()],
-		],
+	"""Name of a ``doctype`` record linked to the party that matches ``filters``, ignoring case."""
+	if not all(filters.values()):
+		return None
+
+	record = frappe.qb.DocType(doctype)
+	link = frappe.qb.DocType("Dynamic Link")
+	query = (
+		frappe.qb.from_(record)
+		.join(link)
+		.on((link.parent == record.name) & (link.parenttype == doctype))
+		.select(record.name)
+		.where((link.link_doctype == link_doctype) & (link.link_name == link_name))
+		.limit(1)
 	)
+	# MariaDB ignores case when comparing text and PostgreSQL doesn't, so compare in lower case.
+	for field, value in filters.items():
+		query = query.where(Lower(record[field]) == cstr(value).lower())
+
+	result = query.run()
+	return result[0][0] if result else None
 
 
 def _demote_other_primary_contacts(link_doctype: str, link_name: str, keep: str) -> None:

erpnext/utilities/test_party_import_provider.py

@@ -109,6 +109,8 @@ class TestPartyImportProvider(ERPNextTestSuite):
 			"Customer", name, ["customer_primary_contact", "customer_primary_address"]
 		)
 
+		# Same records typed in a different case still match, on MariaDB and PostgreSQL alike.
+		values[4:7] = ["REIMPORT@EXAMPLE.COM", "1 MAIN ST", "berlin"]
 		self.run_import("Customer", UPDATE, [["ID", *columns], [name, *values]])
 
 		self.assertEqual(len(self.linked("Contact", "Customer", name)), 1)