Refactor: replace count() > 0 check with exists() (#24583)

Co-authored-by: Yongtao Huang <99629139+hyongtao-db@users.noreply.github.com>
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>

api/controllers/console/app/message.py

@@ -3,6 +3,7 @@ import logging
 from flask_login import current_user
 from flask_restx import Resource, fields, marshal_with, reqparse
 from flask_restx.inputs import int_range
+from sqlalchemy import exists, select
 from werkzeug.exceptions import Forbidden, InternalServerError, NotFound
 
 from controllers.console import api
@@ -94,21 +95,18 @@ class ChatMessageListApi(Resource):
                 .all()
             )
 
-        has_more = False
         if len(history_messages) == args["limit"]:
             current_page_first_message = history_messages[-1]
-            rest_count = (
-                db.session.query(Message)
-                .where(
+
+        has_more = db.session.scalar(
+            select(
+                exists().where(
                     Message.conversation_id == conversation.id,
                     Message.created_at < current_page_first_message.created_at,
                     Message.id != current_page_first_message.id,
                 )
-                .count()
             )
-
-            if rest_count > 0:
-                has_more = True
+        )
 
         history_messages = list(reversed(history_messages))