diff --git a/PostgreSQL/prism/prism.sql b/PostgreSQL/prism/prism.sql
index 76e9a12..37e537d 100644
--- a/PostgreSQL/prism/prism.sql
+++ b/PostgreSQL/prism/prism.sql
@@ -1,9 +1,5 @@
--- 获取最新的数据
-select to_timestamp(max(timestamp))
-from activities;
-
--- 获取最旧的数据
-select to_timestamp(min(timestamp))
+-- 获取最旧于最新的数据
+select to_timestamp(min(timestamp)) as min, to_timestamp(max(timestamp)) as max
 from activities;
 
 -- 最大与最小id