From 9cb6c0be2f05dc5db4b3c37e2e23d52da6b45f29 Mon Sep 17 00:00:00 2001
From: Spade  A <71589810+SpadeA-Tang@users.noreply.github.com>
Date: Tue, 21 Oct 2025 10:38:29 +0800
Subject: [PATCH] fix: fix "at most one distinct index is allowed per field" in
 STRUCT index [2.6] (#44970)

master: https://github.com/milvus-io/milvus/pull/44969
issue: https://github.com/milvus-io/milvus/issues/42148

Signed-off-by: SpadeA <tangchenjie1210@gmail.com>
---
 internal/datacoord/index_service.go | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/internal/datacoord/index_service.go b/internal/datacoord/index_service.go
index 8181a15edb..a147200750 100644
--- a/internal/datacoord/index_service.go
+++ b/internal/datacoord/index_service.go
@@ -59,6 +59,13 @@ func (s *Server) getFieldNameByID(schema *schemapb.CollectionSchema, fieldID int
 			return field.Name, nil
 		}
 	}
+	for _, structField := range schema.GetStructArrayFields() {
+		for _, subField := range structField.GetFields() {
+			if subField.FieldID == fieldID {
+				return subField.Name, nil
+			}
+		}
+	}
 	return "", nil
 }