From c52b15aad0f4797529330f3361f7fe7b65ec3c1f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E9=97=AB=E7=BB=A7=E5=91=A8?= <yan6820@outlook.com>
Date: Tue, 24 Oct 2023 21:26:23 +0800
Subject: [PATCH] =?UTF-8?q?20231017=E7=AC=94=E8=AE=B0=E8=A1=A5=E4=BA=A4?=
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diff --git "a/33\351\227\253\347\273\247\345\221\250/20231017\347\254\224\350\256\260.md" "b/33\351\227\253\347\273\247\345\221\250/20231017\347\254\224\350\256\260.md"
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--- /dev/null
+++ "b/33\351\227\253\347\273\247\345\221\250/20231017\347\254\224\350\256\260.md"
@@ -0,0 +1,20 @@
+#  笔记
+
+##### timestampdiff(单位,a,b); (b-a)时间戳
+
+ 单位：年差year、月差month、天数day、时差hour、分minute、秒second、毫秒microsecond
+
+### 窗口大小
+
+```mysql
+	-- 开窗范围
+	over(partition by 字段 rows between unbounded/preceding and current row)
+	
+	rows:启用窗口大小
+	between...and... :区间范围
+	n unbounded: 后n行
+	n preceding: 前n行
+	current row: 当前行
+	n following: 指当前行之后的行   -- 1 following （当前行+后一行）
+	unbounded following: 最终行
+```
\ No newline at end of file
-- 
Gitee