fix: optimize SQL queries for token usage and top questions with improved username handling

Author: wxg0103

apps/application/sql/get_token_usage.sql

@@ -1,12 +1,9 @@
-
-SELECT
-    SUM(application_chat_record.message_tokens + application_chat_record.answer_tokens) as "token_usage",
-    COALESCE(application_chat.asker->>'username', '游客') as "username"
-FROM
-    application_chat_record application_chat_record
-    LEFT JOIN application_chat application_chat ON application_chat."id" = application_chat_record.chat_id
-${default_sql}
+SELECT SUM(application_chat_record.message_tokens + application_chat_record.answer_tokens) as "token_usage",
+       MAX(COALESCE(application_chat.asker ->>'username', '游客'))                         as "username"
+FROM application_chat_record application_chat_record
+         LEFT JOIN application_chat application_chat ON application_chat."id" = application_chat_record.chat_id
+    ${default_sql}
 GROUP BY
-    COALESCE(application_chat.asker->>'username', '游客')
+    application_chat.chat_user_id
 ORDER BY
     "token_usage" DESC

apps/application/sql/top_questions.sql

@@ -1,10 +1,10 @@
-SELECT COUNT(application_chat_record."id")                          AS chat_record_count,
-       COALESCE(application_chat.asker ->>'username', '游客') AS username
+SELECT COUNT(application_chat_record."id")                         AS chat_record_count,
+       MAX(COALESCE(application_chat.asker ->>'username', '游客')) as "username"
 FROM application_chat_record application_chat_record
          LEFT JOIN application_chat application_chat ON application_chat."id" = application_chat_record.chat_id
     ${default_sql}
 GROUP BY
-    COALESCE (application_chat.asker->>'username', '游客')
+    application_chat.chat_user_id
 ORDER BY
     chat_record_count DESC,
     username ASC