27. Most Common Default Languages

Solution ↗

Medium

Tables: videos

+-------------------------+-------------+
| Column Name             | Type        |
+-------------------------+-------------+
| video_id                | varchar     |
| channel_id              | varchar     |
| title                   | varchar     |
| published_at            | datetime    |
+-------------------------+-------------+
videos contains one row per video.
video_id is the primary key for this table.
channel_id is a foreign key referencing channels.channel_id.

Write a SQL query to list languages from default_language ordered by most frequently used.

Hint

Tip: Ignore NULLs before grouping.

Input:

videos table:
+----------+------------+-------------------+---------------------+
| video_id | channel_id | title             | published_at        |
+----------+------------+-------------------+---------------------+
| V1       | C101       | Python Basics     | 2024-01-11 10:00:00 |
| V2       | C101       | Tableau Project   | 2024-03-05 10:00:00 |
| V3       | C102       | SQL Joins         | 2024-04-10 09:00:00 |
| V4       | C102       | Window Functions  | 2024-05-01 09:00:00 |
| V5       | C103       | Intro to MySQL    | 2024-02-07 11:30:00 |
+----------+------------+-------------------+---------------------+

Output:

Output:
+------------------+--------------+
| default_language | total_videos |
+------------------+--------------+
| en               | 5            |
+------------------+--------------+

Explanation:

Languages are counted after filtering out NULL values.