How to find the top three column totals using SQL

问题

Trying to sum all columns in my table and to find the top 3 of them.

columns have only a value of 1 or 0. That's why I am trying to sum the all inputs to compare them with each other.

I've stucked with order by code integrated into sum()

SELECT (ID)
FROM Student
ORDER BY SUM(C1), SUMC(C2)...SUM(C10)
lIMIT 3

回答1:

If I understand correctly, you can use union all to calculate the sum for each column and then order by and limit:

select c.*
from ((select 'col1', sum(col1) as s from t) union all
      (select 'col2', sum(col2) as s from t) union all
      . . . 
      (select 'col10', sum(col10) as s from t)
     ) c
order by s desc
limit 3;

回答2:

try -

    SELECT TOP 3 (ID)
    FROM Student
    GROUP BY (ID)
    ORDER BY SUM(C1), SUMC(C2)...SUM(C10) DESC

来源：https://stackoverflow.com/questions/56326146/how-to-find-the-top-three-column-totals-using-sql