From 5790bd3150445c53c50fa6419c8290f2f5f8e64c Mon Sep 17 00:00:00 2001
From: mba1398 <26516464+mba1398@users.noreply.github.com>
Date: Mon, 12 Jul 2021 14:26:57 +0800
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diff --git a/ch08: 秋招秘籍 C.md b/ch08: 秋招秘籍 C.md
index c99c963..685ea73 100644
--- a/ch08: 秋招秘籍 C.md	
+++ b/ch08: 秋招秘籍 C.md	
@@ -44,7 +44,31 @@
 |  2021-1-3  |     负    |
 +------------+-----------+
 ```
-
+# 练习三：连续登录
+
+有用户表行为记录表t_act_records表，包含两个字段：uid（用户ID），imp_date（日期）
+
+1. 计算2021年每个月，每个用户连续登录的最多天数
+2. 计算2021年每个月，连续2天都有登录的用户名单
+3. 计算2021年每个月，连续5天都有登录的用户数
+
+构造表mysql如下：
+```sql
+DROP TABLE if EXISTS t_act_records;
+CREATE TABLE t_act_records
+(uid  VARCHAR(20),
+imp_date DATE);
+
+INSERT INTO t_act_records VALUES('u1001', 20210101);
+INSERT INTO t_act_records VALUES('u1002', 20210101);
+INSERT INTO t_act_records VALUES('u1003', 20210101);
+INSERT INTO t_act_records VALUES('u1003', 20210102);
+INSERT INTO t_act_records VALUES('u1004', 20210101);
+INSERT INTO t_act_records VALUES('u1004', 20210102);
+INSERT INTO t_act_records VALUES('u1004', 20210103);
+INSERT INTO t_act_records VALUES('u1004', 20210104);
+INSERT INTO t_act_records VALUES('u1004', 20210105);
+```