【Leetcode】Delete Duplicate Emails

题目链接：https://leetcode.com/problems/delete-duplicate-emails/

题目：

Write a SQL query to delete all duplicate email entries in a table named Person, keeping only unique emails based on its smallest Id.

+—-+——————+

| Id | Email |

+—-+——————+

| 1 | [email protected] |

| 2 | [email protected] |

| 3 | [email protected] |

+—-+——————+

Id is the primary key column for this table.

For example, after running your query, the above Person table should have the following rows:

+—-+——————+

| Id | Email |

+—-+——————+

| 1 | [email protected] |

| 2 | [email protected] |

+—-+——————+

思路：

注意delete后面查询结构的用法。

算法：

delete p1 from Person p1 inner join Person p2 on p1.email=p2.email and p1.id>p2.id

时间： 2024-08-03 04:50:57

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