Getting the avg of the top 10 students from each school
- by dave
Hi all --
We have a school district with 38 elementary schools. The kids took a test. The averages for the schools are widely dispersed, but I want to compare the averages of JUST THE TOP 10 students from each school.
Requirement: use temporary tables only.
I have done this in a very work-intensive, error-prone sort of way as follows.
(sch_code = e.g., 9043;
-- schabbrev = e.g., "Carter";
-- totpct_stu = e.g., 61.3)
DROP TEMPORARY TABLE IF EXISTS avg_top10 ;
CREATE TEMPORARY TABLE avg_top10
( sch_code VARCHAR(4),
schabbrev VARCHAR(75),
totpct_stu DECIMAL(5,1)
);
INSERT
INTO avg_top10
SELECT sch_code
, schabbrev
, totpct_stu
FROM test_table
WHERE sch_code IN ('5489')
ORDER
BY totpct_stu DESC
LIMIT 10;
-- I do that last query for EVERY school, so the total
-- length of the code is well in excess of 300 lines.
-- Then, finally...
SELECT schabbrev, ROUND( AVG( totpct_stu ), 1 ) AS top10
FROM avg_top10
GROUP
BY schabbrev
ORDER
BY top10 ;
-- OUTPUT:
-----------------------------------
schabbrev avg_top10
---------- ---------
Goulding 75.4
Garth 77.7
Sperhead 81.4
Oak_P 83.7
Spring 84.9
-- etc...
Question: So this works, but isn't there a lot better way to do it?
Thanks!
PS -- Looks like homework, but this is, well...real.
