leetcode sql

Author: chaithrakc

leetcode/easy/p182duplicate_emails.sql

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+/*
+https://leetcode.com/problems/duplicate-emails/
+
+Table: Person
+
++-------------+---------+
+| Column Name | Type    |
++-------------+---------+
+| id          | int     |
+| email       | varchar |
++-------------+---------+
+id is the primary key column for this table.
+Each row of this table contains an email. The emails will not contain uppercase letters.
+ 
+
+Write an SQL query to report all the duplicate emails.
+
+Return the result table in any order.
+
+The query result format is in the following example.
+
+Example 1:
+
+Input: 
+Person table:
++----+---------+
+| id | email   |
++----+---------+
+| 1  | a@b.com |
+| 2  | c@d.com |
+| 3  | a@b.com |
++----+---------+
+Output: 
++---------+
+| Email   |
++---------+
+| a@b.com |
++---------+
+Explanation: a@b.com is repeated two times.
+*/
+
+select email
+from person
+group by email
+having count(email) > 1;
+
+/*
+input: {"headers": {"Person": ["id", "email"]}, 
+"rows": {"Person": [[1, "a@b.com"], [2, "c@d.com"], [3, "a@b.com"]]}}
+
+output:
+{"headers": ["email"], "values": [["a@b.com"]]}
+*/