<div id="readability-page-1" class="page"><div>
            <h2 id="problem">Problem</h2><figure><a href="https://leetcode.com/problems/ads-performance/description/"><div><p>LeetCode - The World’s Leading Online Programming Learning Platform</p><p>Level up your coding skills and quickly land a job. This is the best place to expand your knowledge and get prepared for your next interview.</p><p><img src="https://leetcode.com/favicon.ico" alt=""><span>LeetCode</span></p></div><p><img src="https://leetcode.com/static/images/LeetCode_Sharing.png" alt=""></p></a></figure><h2 id="solution">Solution</h2><pre><code>SELECT ad_id, 
    CASE
        WHEN clicked = 0 AND viewed = 0 THEN 0
        ELSE ROUND(clicked / (clicked + viewed) * 100, 2)
    END as ctr
FROM (
        SELECT ad_id, 
            IFNULL(SUM(CASE WHEN action = 'Clicked' THEN cnt END),0) AS clicked,
            IFNULL(SUM(CASE WHEN action = 'Viewed' THEN cnt END),0) AS viewed,
            IFNULL(SUM(CASE WHEN action = 'Ignored' then cnt END),0) AS ignored
        FROM (
        SELECT ad_id, action, COUNT(*) as cnt
        FROM Ads
        GROUP BY ad_id, action
        ) as Temp
        GROUP BY ad_id
) as Temp
ORDER BY ctr DESC, ad_id</code></pre>
        </div></div>

일시불 프로그래밍

Problem
Solution
SELECT ad_id, 
    CASE
        WHEN clicked = 0 AND viewed = 0 THEN 0
        ELSE ROUND(clicked / (clicked + viewed) * 100, 2)
    END as ctr
FROM (
        SELECT ad_id, 
            IFNULL(SUM(CASE WHEN action = 'Clicked' THEN cnt END),0) AS clicked,
            IFNULL(SUM(CASE WHEN action = 'Viewed' THEN cnt END),0) AS viewed,
            IFNULL(SUM(CASE WHEN action = 'Ignored' then cnt END),0) AS ignored
        FROM (
        SELECT ad_id, action, COUNT(*) as cnt
        FROM Ads
        GROUP BY ad_id, action
        ) as Temp
        GROUP BY ad_id
) as Temp
ORDER BY ctr DESC, ad_id

1322. Ads Performance

댓글