diff --git a/chat2db-server/chat2db-server-web/chat2db-server-web-api/src/main/java/ai/chat2db/server/web/api/controller/ai/ChatController.java b/chat2db-server/chat2db-server-web/chat2db-server-web-api/src/main/java/ai/chat2db/server/web/api/controller/ai/ChatController.java
index cfb00878..73f4f83e 100644
--- a/chat2db-server/chat2db-server-web/chat2db-server-web-api/src/main/java/ai/chat2db/server/web/api/controller/ai/ChatController.java
+++ b/chat2db-server/chat2db-server-web/chat2db-server-web-api/src/main/java/ai/chat2db/server/web/api/controller/ai/ChatController.java
@@ -599,6 +599,9 @@ public class ChatController {
                     schemas.add(data.getTableSchema());
                 }
             }
+            if (CollectionUtils.isEmpty(schemas)) {
+                return "";
+            }
             String res = JSON.toJSONString(schemas);
             log.info("search vector result:{}", res);
             return res;
@@ -636,6 +639,9 @@ public class ChatController {
                     schemas.add(data.getTableSchemaContent());
                 }
             }
+            if (CollectionUtils.isEmpty(schemas)) {
+                return "";
+            }
             String res = JSON.toJSONString(schemas);
             log.info("search es result:{}", res);
             return res;