diff --git a/frappe/tests/test_query_builder.py b/frappe/tests/test_query_builder.py
index 9375d17ef2..a8befd0541 100644
--- a/frappe/tests/test_query_builder.py
+++ b/frappe/tests/test_query_builder.py
@@ -4,6 +4,7 @@ from datetime import time
 
 import frappe
 from frappe.core.doctype.doctype.test_doctype import new_doctype
+from frappe.database.operator_map import func_in
 from frappe.query_builder import Case
 from frappe.query_builder.builder import Function
 from frappe.query_builder.custom import ConstantColumn
@@ -503,3 +504,70 @@ class TestMisc(IntegrationTestCase):
 		roles = frappe.qb.from_(role).select(role.name)
 
 		self.assertEqual(set(users.run() + roles.run()), set((users + roles).run()))
+
+
+class TestOperatorIn(IntegrationTestCase):
+	def test_func_in_without_empty_values(self):
+		note = frappe.qb.DocType("Note")
+		query = func_in(note.name, ["n1", "n2", "n3"])
+		sql_str = str(query).lower()
+
+		self.assertIn("in", sql_str)
+		self.assertNotIn("coalesce", sql_str)
+
+	def test_func_in_with_none_converts_to_empty_string(self):
+		note = frappe.qb.DocType("Note")
+		query = func_in(note.name, [None, "user1"])
+		sql_str = str(query).lower()
+
+		self.assertIn("coalesce", sql_str)
+		self.assertIn("''", sql_str)
+
+	def test_func_in_with_empty_string_uses_coalesce(self):
+		note = frappe.qb.DocType("Note")
+		query = func_in(note.name, ["", "user1"])
+		sql_str = str(query).lower()
+
+		self.assertIn("coalesce", sql_str)
+		self.assertIn("''", sql_str)
+
+	def test_func_in_with_mixed_none_and_values(self):
+		note = frappe.qb.DocType("Note")
+		query = func_in(note.name, ["val1", None, "val2"])
+		sql_str = str(query).lower()
+
+		self.assertIn("coalesce", sql_str)
+
+	def test_in_filter_matches_null_and_empty_columns(self):
+		test_doctype = new_doctype(
+			fields=[
+				{
+					"fieldname": "test_field",
+					"fieldtype": "Data",
+					"label": "Test Field",
+				},
+			],
+		)
+		test_doctype.insert()
+		self.test_doctype_name = test_doctype.name
+		self.addCleanup(frappe.delete_doc, "DocType", self.test_doctype_name)
+
+		frappe.db.sql(f"DELETE FROM `tab{self.test_doctype_name}`")
+		frappe.db.commit()
+
+		doc_null = frappe.get_doc({"doctype": self.test_doctype_name, "test_field": None})
+		doc_null.insert()
+		doc_empty = frappe.get_doc({"doctype": self.test_doctype_name, "test_field": ""})
+		doc_empty.insert()
+		doc_user = frappe.get_doc({"doctype": self.test_doctype_name, "test_field": "user1"})
+		doc_user.insert()
+
+		results = frappe.get_all(
+			self.test_doctype_name,
+			filters={"test_field": ["in", [None, "user1"]]},
+			pluck="test_field",
+		)
+
+		self.assertIn(None, results)
+		self.assertIn("", results)
+		self.assertIn("user1", results)