Project Notes

Delete Duplicate Emails

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Description

tab: English
 
<p>Table: <code>Person</code></p>
 
<pre>
+-------------+---------+
| Column Name | Type    |
+-------------+---------+
| id          | int     |
| email       | varchar |
+-------------+---------+
id is the primary key (column with unique values) for this table.
Each row of this table contains an email. The emails will not contain uppercase letters.
</pre>
 
<p>&nbsp;</p>
 
<p>Write a solution to<strong> delete</strong> all duplicate emails, keeping only one unique email with the smallest <code>id</code>.</p>
 
<p>For SQL users, please note that you are supposed to write a <code>DELETE</code> statement and not a <code>SELECT</code> one.</p>
 
<p>For Pandas users, please note that you are supposed to modify <code>Person</code> in place.</p>
 
<p>After running your script, the answer shown is the <code>Person</code> table. The driver will first compile and run your piece of code and then show the <code>Person</code> table. The final order of the <code>Person</code> table <strong>does not matter</strong>.</p>
 
<p>The result format is in the following example.</p>
 
<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>
 
<pre>
<strong>Input:</strong> 
Person table:
+----+------------------+
| id | email            |
+----+------------------+
| 1  | john@example.com |
| 2  | bob@example.com  |
| 3  | john@example.com |
+----+------------------+
<strong>Output:</strong> 
+----+------------------+
| id | email            |
+----+------------------+
| 1  | john@example.com |
| 2  | bob@example.com  |
+----+------------------+
<strong>Explanation:</strong> john@example.com is repeated two times. We keep the row with the smallest Id = 1.
</pre>
 
 
 
---
 
[submissions](https://leetcode.com/problems/delete-duplicate-emails/submissions/) | [solutions](https://leetcode.com/problems/delete-duplicate-emails/solutions/)
 
 
tab: 中文
 
<p>表:&nbsp;<code>Person</code></p>
 
<pre>
+-------------+---------+
| Column Name | Type    |
+-------------+---------+
| id          | int     |
| email       | varchar |
+-------------+---------+
id 是该表的主键列(具有唯一值的列)。
该表的每一行包含一封电子邮件。电子邮件将不包含大写字母。
</pre>
 
<p>&nbsp;</p>
 
<p>编写解决方案<strong> 删除</strong> 所有重复的电子邮件，只保留一个具有最小 <code>id</code> 的唯一电子邮件。</p>
 
<p>（对于 SQL 用户，请注意你应该编写一个 <code>DELETE</code> 语句而不是 <code>SELECT</code> 语句。）</p>
 
<p>（对于 Pandas 用户，请注意你应该直接修改 <code>Person</code> 表。）</p>
 
<p>运行脚本后，显示的答案是 <code>Person</code> 表。驱动程序将首先编译并运行您的代码片段，然后再显示 <code>Person</code> 表。<code>Person</code> 表的最终顺序 <strong>无关紧要</strong> 。</p>
 
<p>返回结果格式如下示例所示。</p>
 
<p>&nbsp;</p>
 
<p><strong class="example">示例 1:</strong></p>
 
<pre>
<strong>输入:</strong> 
Person 表:
+----+------------------+
| id | email            |
+----+------------------+
| 1  | john@example.com |
| 2  | bob@example.com  |
| 3  | john@example.com |
+----+------------------+
<strong>输出:</strong> 
+----+------------------+
| id | email            |
+----+------------------+
| 1  | john@example.com |
| 2  | bob@example.com  |
+----+------------------+
<strong>解释:</strong> john@example.com重复两次。我们保留最小的Id = 1。</pre>
 
 
 
---
 
[提交记录](https://leetcode.cn/problems/delete-duplicate-emails/submissions/) | [题解](https://leetcode.cn/problems/delete-duplicate-emails/solution/)

Solutions & Notes

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