How to get a nested subquery to recognize a parent query column

Question

I have a problem when I try to calculate the sum of the values ​​for each identifier. I decided to do this using subqueries (typically I would use a join, but I also keep a counter for each subquery for clipping purposes - see this question for more information). For this question, suppose I have the following MySQL query:

/* 1.  */  SELECT 
/* 2.  */      t1.experiement_id,
/* 3.  */      (SELECT  sum(x.size) 
/* 4.  */       FROM    (SELECT size, ( @rownum := @rownum + 1 ) AS `rownum`
/* 5.  */                FROM   data AS t0 
/* 6.  */                JOIN ( select @rownum := 0 ) 
/* 7.  */                WHERE  t0.experiment_id = t1.experiment_id
/* 8.  */                ORDER BY size) AS x
/* 9.  */                WHERE x.rownum <= t2.clip_index ) AS `sum`
/* 10. */  
/* 11. */  FROM data      AS t1
/* 12. */  JOIN data_clip AS t2 USING (experiment_id)
/* 13. */  
/* 14. */  GROUP BY t1.experiment_id

7, , experiement_id. , t1.experiement_id . , 1 . , , , t2.clip_index . # 7, ( ). , ? .

Answer 1

- ?

(SELECT sum(size) FROM  data AS t0                  
WHERE  t0.experiment_id = t1.experiment_id
ORDER BY size HAVING COUNT(*)<=t2.clip_index
) AS `sum` 

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