How to Fix MySQL's 'LIMIT & IN/ALL/ANY/SOME subquery' Error Using JOINs?

MySQL Nested Query Error: 'LIMIT & IN/ALL/ANY/SOME subquery' Not Supported

This error occurs when attempting to use a subquery with a LIMIT clause within an IN clause in MySQL. To resolve this issue, an alternative approach is to utilize a JOIN:

Original Code:

$Last_Video         = $db->fetch_all('
SELECT VID, thumb
FROM video
WHERE VID IN (
    SELECT VID
    FROM video
    WHERE title LIKE "%'.$Channel['name'].'%"
    ORDER BY viewtime DESC
    LIMIT 5)
ORDER BY RAND()
LIMIT 1
');

Refactored Code with JOIN:

SELECT v.VID, v.thumb
FROM video AS v
INNER JOIN
     (SELECT VID
     FROM video
     WHERE title LIKE "%'.$Channel['name'].'%"
     ORDER BY viewtime DESC
     LIMIT 5) as v2
  ON v.VID = v2.VID
ORDER BY RAND()
LIMIT 1

Explanation:

The JOIN operation links the two tables (video and v2) based on the common VID column. This eliminates the need for the nested query with a LIMIT clause within the IN clause, which is not supported in the current MySQL version.

Benefits of JOIN:

• Improved performance by reducing the number of database queries.
• Simpler and more readable query structure.
• Support for more complex query scenarios with multiple tables and conditions.

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