feat: add sql solution to lc problem: No.1322 (#746)

No.1322. Ads Performance

Author: Dhoni77

solution/1300-1399/1322.Ads Performance/README.md

@@ -77,7 +77,17 @@ action 列是一个枚举类型 ('Clicked', 'Viewed', 'Ignor
 ### **SQL**
 
 ```sql
-
+SELECT
+  ad_id,
+  Ifnull(ROUND(AVG(CASE
+    WHEN action = 'Clicked' THEN 1
+    WHEN action = 'Viewed' THEN 0
+    ELSE NULL
+  END) * 100, 2), 0) AS ctr
+FROM ads
+GROUP BY ad_id
+ORDER BY ctr DESC,
+ad_id ASC;
 ```
 
 <!-- tabs:end -->

solution/1300-1399/1322.Ads Performance/README_EN.md

@@ -75,7 +75,17 @@ Note that we do not care about Ignored Ads.
 ### **SQL**
 
 ```sql
-
+SELECT
+  ad_id,
+  Ifnull(ROUND(AVG(CASE
+    WHEN action = 'Clicked' THEN 1
+    WHEN action = 'Viewed' THEN 0
+    ELSE NULL
+  END) * 100, 2), 0) AS ctr
+FROM ads
+GROUP BY ad_id
+ORDER BY ctr DESC,
+ad_id ASC;
 ```
 
 <!-- tabs:end -->

solution/1300-1399/1322.Ads Performance/Solution.sql

@@ -0,0 +1,12 @@
+# Write your MySQL query statement below
+SELECT
+  ad_id,
+  Ifnull(ROUND(AVG(CASE
+    WHEN action = 'Clicked' THEN 1
+    WHEN action = 'Viewed' THEN 0
+    ELSE NULL
+  END) * 100, 2), 0) AS ctr
+FROM ads
+GROUP BY ad_id
+ORDER BY ctr DESC,
+ad_id ASC;