How to Retrieve Maximum Value and Associated Columns in SQL Subqueries?

Maximum Value Subqueries in SQL

In this query, you seek to retrieve the corresponding values for columns based on the maximum value of another column. While your original approach uses a GROUP BY statement, it only reliably fetches the maximum video ID but not the related data from other columns.

To address this, consider utilizing a subquery that identifies the distinct maximum video IDs per category. The modified query below adheres to this approach:

SELECT
    *
FROM
    videos
WHERE
    video_id IN
    (
        SELECT
            DISTINCT
            MAX(video_id)
        FROM
            videos
        GROUP BY
            video_category
    ) 
ORDER BY
    video_category ASC

In this query, a subquery is employed to isolate the set of maximum video IDs. The table is then filtered using this set to retrieve all columns for the corresponding maximum video IDs. By leveraging the IN operator and concatenating the results, this query efficiently fetches the desired values.

Alternatively, you can use a join operation to achieve the same result, as shown below:

SELECT
   s.video_id
   ,s.video_category
   ,s.video_url
   ,s.video_date
   ,s.video_title
   ,s.short_description
FROM videos s
   JOIN (SELECT MAX(video_id) AS id FROM videos GROUP BY video_category) max
      ON s.video_id = max.id

This approach utilizes a join to match the maximum video ID rows with the corresponding rows from the videos table, retrieving the complete set of columns for each maximum video ID. Both solutions effectively address the issue by capturing the values associated with the maximum video IDs in each category.

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