feat: add sql solution to lc problem: No.1369 (doocs#797)

No.1369.Get the Second Most Recent Activity

Author: Dhoni77

solution/1300-1399/1369.Get the Second Most Recent Activity/README.md

@@ -67,7 +67,18 @@ Bob 只有一条记录，我们就取这条记录</pre>
 ### **SQL**
 
 ```sql
-
+SELECT
+  username,
+  activity,
+  startdate,
+  enddate
+FROM (SELECT
+  *,
+  RANK() OVER (PARTITION BY username ORDER BY startdate DESC) rk,
+  COUNT(username) OVER (PARTITION BY username) AS cnt
+FROM UserActivity) a
+WHERE a.rk = 2
+OR a.cnt = 1;
 ```
 
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solution/1300-1399/1369.Get the Second Most Recent Activity/README_EN.md

@@ -63,7 +63,18 @@ Bob only has one record, we just take that one.
 ### **SQL**
 
 ```sql
-
+SELECT
+  username,
+  activity,
+  startdate,
+  enddate
+FROM (SELECT
+  *,
+  RANK() OVER (PARTITION BY username ORDER BY startdate DESC) rk,
+  COUNT(username) OVER (PARTITION BY username) AS cnt
+FROM UserActivity) a
+WHERE a.rk = 2
+OR a.cnt = 1;
 ```
 
 <!-- tabs:end -->

solution/1300-1399/1369.Get the Second Most Recent Activity/Solution.sql

@@ -0,0 +1,12 @@
+SELECT
+  username,
+  activity,
+  startdate,
+  enddate
+FROM (SELECT
+  *,
+  RANK() OVER (PARTITION BY username ORDER BY startdate DESC) rk,
+  COUNT(username) OVER (PARTITION BY username) AS cnt
+FROM UserActivity) a
+WHERE a.rk = 2
+OR a.cnt = 1;