g0101_0200.s0196_delete_duplicate_emails.readme.md Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of leetcode-in-kotlin Show documentation
Show all versions of leetcode-in-kotlin Show documentation
Kotlin-based LeetCode algorithm problem solutions, regularly updated
196\. Delete Duplicate Emails
Easy
SQL Schema
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 **delete** all the duplicate emails, keeping only one unique email with the smallest `id`.
Return the result table in **any order**.
The query result format is in the following example.
**Example 1:**
**Input:**
Person table:
+----+------------------+
| id | email |
+----+------------------+
| 1 | [email protected] |
| 2 | [email protected] |
| 3 | [email protected] |
+----+------------------+
**Output:**
+----+------------------+
| id | email |
+----+------------------+
| 1 | [email protected] |
| 2 | [email protected] |
+----+------------------+
**Explanation:** [email protected] is repeated two times. We keep the row with the smallest Id = 1.