Upload 030

Author: ggeerraarrdd

README.md

@@ -70,6 +70,7 @@ ALL CONTENTS IN THIS REPO ARE FOR EDUCATIONAL PURPOSES ONLY.
 | 027   | [Laptop vs. Mobile Viewership](https://datalemur.com/questions/laptop-mobile-viewership)            | [Solution](solutions/027_laptop_vs_mobile_viewership.md) | DataLemur | Easy |   |
 | 028   | [Spotify Streaming History](https://datalemur.com/questions/spotify-streaming-history)              | [Solution](solutions/028_spotify_streaming_history.md) | DataLemur | Medium |   |
 | 029   | [Consecutive Filing Years](https://datalemur.com/questions/consecutive-filing-years)                | [Solution](solutions/029_consecutive_filing_years.md) | DataLemur | Hard |   |
+| 030   | [Average Post Hiatus (Part 1)](https://datalemur.com/questions/sql-average-post-hiatus-1)           | [Solution](solutions/030_average_post_hiatus_part_1.md) | DataLemur | Easy |   |
 
 ## Authors
 

solutions/030_average_post_hiatus_part_1.md

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+# SQL Everyday \#030
+
+## Average Post Hiatus (Part 1)
+
+Site: DataLemur\
+Difficulty per Site: Easy
+
+## Problem
+
+Given a table of Facebook posts, for each user who posted at least twice in 2021, write a query to find the number of days between each user’s first post of the year and last post of the year in the year 2021. Output the user and number of the days between each user's first and last post. [[Full Description](https://datalemur.com/questions/sql-average-post-hiatus-1)]
+
+## Submitted Solution
+
+```sql
+-- Submitted Solution
+WITH cte AS (
+SELECT 
+  user_id
+  ,MIN(post_date) AS date_min
+  ,MAX(post_date) AS date_max
+FROM posts
+WHERE post_date BETWEEN '01/01/2021' AND '01/01/2022'
+GROUP BY user_id
+)
+SELECT
+  user_id
+  ,EXTRACT(DAY FROM date_max - date_min) AS days_between
+FROM cte
+WHERE date_min < date_max
+;
+```
+
+## Site Solution
+
+```sql
+-- DataLemur Solution 
+SELECT 
+	user_id, 
+    MAX(post_date::DATE) - MIN(post_date::DATE) AS days_between
+FROM posts
+WHERE DATE_PART('year', post_date::DATE) = 2021 
+GROUP BY user_id
+HAVING COUNT(post_id)>1;
+```
+
+## Notes
+
+TODO
+
+Go to [Table of Contents](/README.md#contents)\
+Go to [Overview](/README.md)