How to get random records from a pre-filtered list using MySQL subquery?

Question

I searched but couldn't find a working solution. Need a little help here.

Suppose I have a table with more than 100 records. First, I need to find the first 20 records in a certain order, and then I need to randomly pick 5 records from these 20 records. This is my query,

SELECT a 
FROM tableA 
WHERE b IN (
    SELECT b 
    FROM tableA 
    WHERE c="x" 
    ORDER BY d DESC 
    LIMIT 20
) 
ORDER BY RAND() 
LIMIT 5;

Let me know how to correct it. Thanks.

Answer 1

The inner query selects 20 users sorted by ID, the outer query uses the RAND() function to randomly order, with a limit of 5 :)

SELECT * FROM 
(
    SELECT * FROM A ORDER BY id desc LIMIT 20
) T1
ORDER BY rand() limit 5