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1148. 文章浏览 I

Views 表:

+---------------+---------+
| Column Name   | Type    |
+---------------+---------+
| article_id    | int     |
| author_id     | int     |
| viewer_id     | int     |
| view_date     | date    |
+---------------+---------+
此表无主键,因此可能会存在重复行。
此表的每一行都表示某人在某天浏览了某位作者的某篇文章。
请注意,同一人的 author_id 和 viewer_id 是相同的。

 

请编写一条 SQL 查询以找出所有浏览过自己文章的作者,结果按照 id 升序排列。

查询结果的格式如下所示:

Views 表:
+------------+-----------+-----------+------------+
| article_id | author_id | viewer_id | view_date  |
+------------+-----------+-----------+------------+
| 1          | 3         | 5         | 2019-08-01 |
| 1          | 3         | 6         | 2019-08-02 |
| 2          | 7         | 7         | 2019-08-01 |
| 2          | 7         | 6         | 2019-08-02 |
| 4          | 7         | 1         | 2019-07-22 |
| 3          | 4         | 4         | 2019-07-21 |
| 3          | 4         | 4         | 2019-07-21 |
+------------+-----------+-----------+------------+

结果表:
+------+
| id   |
+------+
| 4    |
| 7    |
+------+

原站题解

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上次编辑到这里,代码来自缓存 点击恢复默认模板
# Write your MySQL query statement below

mysql 解法, 执行用时: 414 ms, 内存消耗: 0 B, 提交时间: 2022-06-02 10:00:24

# Write your MySQL query statement below
select distinct author_id as id from views where author_id=viewer_id order by id asc;

mysql 解法, 执行用时: 425 ms, 内存消耗: 0 B, 提交时间: 2022-05-27 11:40:25

# Write your MySQL query statement below
select distinct author_id as id from views where author_id=viewer_id order by id asc;

pythondata 解法, 执行用时: 320 ms, 内存消耗: 60.5 MB, 提交时间: 2023-08-07 16:33:18

import pandas as pd

def article_views(views: pd.DataFrame) -> pd.DataFrame:
    df = views[views['author_id'] == views['viewer_id']]

    df.drop_duplicates(subset=['author_id'], inplace=True)
    df.sort_values(by=['author_id'], inplace=True)
    df.rename(columns={'author_id':'id'}, inplace=True)

    df = df[['id']]

    return df

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