diff --git a/表达式函数.md b/表达式函数.md
index ade306f..6f460e0 100644
--- a/表达式函数.md
+++ b/表达式函数.md
@@ -87,6 +87,11 @@ fsql.Select<T>()
   .Where(a => a.CreateTime.Between(DateTime.Today, DateTime.Today.AddDays(1)))
   .ToList();
 //正常用法应该是这样
+
+fsql.Select<T>()
+  .Where(a => a.CreateTime.Subtract(DateTime.Today).TotalDays == 0)
+  .ToList();
+//WHERE datediff(day, date1, date2) = 0
 ```
 
 > SqlServer nvarchar/varchar 已兼容表达式解析，分别解析为：N'' 和 ''，优化索引执行计划；