이지영: [SQL] Confirmation Rate_241211

Author: yeongleej

SQL/14주차/JY_Confirmation_Rate.sql

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+-- 1934. Confirmation Rate
+-- https://leetcode.com/problems/confirmation-rate/
+SELECT a.user_id
+       , CASE
+            WHEN COUNT(IF(action = "confirmed", a.user_id, null)) = 0 THEN round(0, 2)
+            ELSE ROUND(COUNT(IF(action = "confirmed", a.user_id, null)) / count(*), 2)
+         END AS confirmation_rate
+FROM signups a
+LEFT JOIN confirmations b
+ON a.user_id = b.user_id
+GROUP BY a.user_id