SQL Adventure: Article Views Challenge

Hello, SQL enthusiasts! Today, we’re tackling a fun problem from the LeetCode SQL 50 list: Article Views I. It’s time to dive into the world of self-obsessed authors who love viewing their own articles. 📚😆

The Quest for Self-Viewing Authors 🕵️‍♂️

Imagine we have a table called views that logs every time someone views an article. Our mission is to find authors who view their own articles. Yes, you heard it right—authors who can’t resist revisiting their own masterpieces! Let’s take a look at our views table:

Table Structure

Column Name	Type
article_id	int
author_id	int
viewer_id	int
view_date	date

Each row in this table indicates that some viewer viewed an article (written by some author) on some date. Note that equal author_id and viewer_id indicate the same person.

Sample Data

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

The SQL Sorcery 🪄

To uncover these self-obsessed authors, we’ll use this magical SQL query:

SELECT DISTINCT author_id AS id 
FROM views
WHERE author_id = viewer_id 
ORDER BY author_id;

Decoding the Spell 🔍

Let’s break down our query step by step:

SELECT DISTINCT author_id AS id: We want to retrieve unique author_ids, and we’re renaming the column to id for simplicity.
FROM views: This specifies that our data source is the views table.
WHERE author_id = viewer_id: This condition filters our results to include only those rows where the author viewed their own article.
ORDER BY author_id: This sorts the results by author_id.

Why It Works 📊

Our query is designed to find unique authors who viewed their own articles. The DISTINCT keyword ensures we don’t get duplicate entries, even if an author has viewed their own articles multiple times. It’s like finding the super fans among authors—those who are their own biggest admirers! 🥳

Example Time! 🎉

Let’s apply our SQL query to our sample views table. Here’s how it works:

Input Table:

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

Running Our Query:

When we run our SQL query, it scans through the views table and filters the rows based on our conditions. The magic happens!

Output Table:

id
4
7

And there we have it! 🎊 Authors 4 and 7 are our self-viewing champions!

Real-World Applications 🌏

Understanding how to filter and sort data based on specific criteria is a crucial skill in data analysis. Whether you're analyzing website traffic, sales data, or user interactions, being able to extract meaningful subsets of data can help drive insights and inform decision-making. 🚀📈

Why This Query is Useful 🧠

This query helps us identify patterns in user behavior. For instance, in a blogging platform, knowing which authors frequently revisit their own articles might indicate they are actively engaged with their content, possibly updating and improving it regularly. This kind of insight can be valuable for improving user experience and engagement strategies. 🌟

Final Thoughts 📝

And there you have it, folks! We’ve successfully identified authors who can’t get enough of their own work using a simple yet effective SQL query. Next time you’re working with a dataset, remember that SQL is your trusty tool to uncover interesting patterns and insights. Until next time, happy querying! 🎉

Feel free to share your thoughts, questions, or any other SQL challenges you’d like to tackle. Let’s continue exploring the magical world of databases together! 🌟

Disclaimer: All data used in this example is fictional and for illustrative purposes only.

Article Views I: A SQL Adventure from LeetCode’s Top 50 List 👀💻