feat: add sql solution to lc problem: No.1355 (#1094)

No.1355.Activity Participants

Author: yanglbme

solution/1300-1399/1355.Activity Participants/README.md

@@ -91,7 +91,16 @@ Singing 活动有两个人参加 (Victor J. and Jade W.)</pre>
 ### **SQL**
 
 ```sql
-
+# Write your MySQL query statement below
+WITH
+    t AS (
+        SELECT activity, count(1) AS cnt
+        FROM Friends
+        GROUP BY activity
+    )
+SELECT activity
+FROM t
+WHERE cnt > (SELECT min(cnt) FROM t) AND cnt < (SELECT max(cnt) FROM t);
 ```
 
 <!-- tabs:end -->

solution/1300-1399/1355.Activity Participants/README_EN.md

@@ -87,7 +87,16 @@ Singing is performed by 2 friends (Victor J. and Jade W.)
 ### **SQL**
 
 ```sql
-
+# Write your MySQL query statement below
+WITH
+    t AS (
+        SELECT activity, count(1) AS cnt
+        FROM Friends
+        GROUP BY activity
+    )
+SELECT activity
+FROM t
+WHERE cnt > (SELECT min(cnt) FROM t) AND cnt < (SELECT max(cnt) FROM t);
 ```
 
 <!-- tabs:end -->

solution/1300-1399/1355.Activity Participants/Solution.sql

@@ -0,0 +1,10 @@
+# Write your MySQL query statement below
+WITH
+    t AS (
+        SELECT activity, count(1) AS cnt
+        FROM Friends
+        GROUP BY activity
+    )
+SELECT activity
+FROM t
+WHERE cnt > (SELECT min(cnt) FROM t) AND cnt < (SELECT max(cnt) FROM t);