Calculate Median in query in my PHP

[SaranacLake]

This question may sound like a MySQL question, but I think it relates more to PHP...

Currently I have the following (pseudo-code) query in my PHP script...

	SELECT id, col-a, col-b, col-c,
       usefulCount, usefulResponses, (usefulCount/usefulResposnes) as usefulPct
	       newMedianCalculationHere
	FROM(
     SELECT DISTINCT col-a, col-b, col-c,
	         (SELECT COUNT(xtc.id)
          FROM table-7
          INNER JOIN table-8
          ON
          WHERE something
          AND respone_yn = 1) AS usefulCount,
	         (SELECT COUNT(xtc.id)
          FROM table-7
          INNER JOIN table-8
          ON something
          WHERE something) AS usefulResponses
	          (Add Median calculation here) AS newMedianCalculationHere
	     FROM 
     INNER JOIN
     WHERE
    ) AS wrapper
	ORDER BY whatever
	

 

Now I need to calculate the median of some data and drop that in my inner query.

Here is some sample code that I found online...

https://www.eversql.com/how-to-calculate-median-value-in-mysql-using-a-simple-sql-query/

	SET @rowindex := -1;
	SELECT
	   AVG(g.grade)
	FROM
	   (SELECT @rowindex:=@rowindex + 1 AS rowindex,
	           grades.grade AS grade
	    FROM grades
	    ORDER BY grades.grade) AS g
	WHERE
	g.rowindex IN (FLOOR(@rowindex / 2) , CEIL(@rowindex / 2));
	

 

Because my query is in a PHP script, I'm now sure how to incorporate these lines...

	SET @rowindex := -1;
	 
	(SELECT @rowindex:=@rowindex + 1 AS rowindex,
	

 

Oh, if it matters, I use prepared statements in my PHP...

 

Thanks.