使用php mysql查询选择具有最高值的5列

Question

I need 5 columns with highest values (values must be sum of each column) for report. I have about 40 contury colunms something like england_turist, polad_turists, us_turists, india_turists... eng - 152(sum), pol - 280(sum), us - 54(sum), in - 36(sum)... and query needs to pick pol - 280 and eng - 152. So query need to sum every column and pick 5 columns with highest values.

I got result from here but how to create query

SELECT * FROM
(
     SELECT 'Bmw' AS vrstaautomobila, SUM(bmw) AS brautomobila FROM unos_korisnika
     UNION
     SELECT 'Mercedes' AS vrstaautomobila, SUM(mercedes) AS brautomobila FROM unos_korisnika
     UNION
     SELECT 'Opel' AS vrstaautomobila, SUM(opel) AS brautomobila FROM unos_korisnika
     UNION
     SELECT 'Nissan' AS vrstaautomobila, SUM(nissan) AS brautomobila FROM unos_korisnika
     UNION
     SELECT 'Peguoet' AS vrstaautomobila, SUM(peguoet) AS brautomobila FROM unos_korisnika
     UNION
     SELECT 'Volkswagen' AS vrstaautomobila, SUM(volkswagen) AS brautomobila FROM unos_korisnika
)
AS results
ORDER BY brautomobila DESC
LIMIT 5

Answer 1

Transpose the table (convert columns to rows) and then select the top values.

select * from transposed_table order by value_column desc limit 5

you may use How to transpose mysql table rows into columns to transpose your data or may be this SQL - How to transpose?