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Get the column name that has the maximum value in sql row

I have a table in my database where I store categories for news, and every time a user reads an article, it increases the value in the corresponding column. Like this:

enter image description here

Now I want to run a query where I can get the column names with 4 highest values ​​for each record. For example, for user 9, he will return this:

enter image description here

I tried several things, I searched a lot, but I don’t know how to do it. Can anybody help me?

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4 answers

This should do it:

select
  userid,
  max(case when rank=1 then name end) as `highest value`,
  max(case when rank=2 then name end) as `2nd highest value`,
  max(case when rank=3 then name end) as `3rd highest value`,
  max(case when rank=4 then name end) as `4th highest value`
from
(
  select userID, @rownum := @rownum + 1 AS rank, name, amt from (
    select userID, Buitenland as amt, 'Buitenland' as name from newsarticles where userID = 9 union
    select userID, Economie, 'Economie' from newsarticles where userID = 9 union
    select userID, Sport, 'Sport' from newsarticles where userID = 9 union
    select userID, Cultuur, 'Cultuur' from newsarticles where userID = 9 union
    select userID, Wetenschap, 'Wetenschap' from newsarticles where userID = 9 union
    select userID, Media, 'Media' from newsarticles where userID = 9
  ) amounts, (SELECT @rownum := 0) r
  order by amt desc
  limit 4
) top4
group by userid

Demo: http://www.sqlfiddle.com/#!2/ff624/11

+3
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A very easy way to do this is shown below.

select userId, substring_index(four_highest,',',1) as 'highest value', substring_index(substring_index(four_highest,',',2),',',-1) as '2th highest value',  substring_index(substring_index(four_highest,',',3),',',-1) as '3 rd highest value',  substring_index(four_highest,',',-1) as '4th highest value'   from
(
select userid, convert(group_concat(val) using utf8) as four_highest from
(
select userId,Buitenland as val,'Buitenland' as col from test where userid=9 union
select userId,Economie as val,' Economie' as col from test where   userid=9 union
select userId,Sport as val ,'Sport' as col from test where  userid=9 union
select userId,Cultuur as val,'Cultuur' as col from test where userid=9 union
select userId,Wetenschap as val,'Wetenschap' as col from test where userid=9 union
select userId,Media as val,'Media' as col from test where  userid=9 order by val desc limit 4
) inner_query
)outer_query;
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PL / SQL maybe? Set user_id, query the table, save the returned row in an nx2 array of column names and values ​​(where n is the number of columns) and sort the array based on the values.

Of course, the right thing is to remake your database as @octern suggests.

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This will allow you to start with the concept of capturing the highest value from multiple columns in one row (change for your specific tables - I created a fake).

create table fake 
(
  id int Primary Key,
  col1 int,
  col2 int,
  col3 int,
  col4 int 
)
insert into fake values (1, 5, 9, 27, 10)
insert into fake values (2, 3, 5, 1, 20)
insert into fake values (3, 89, 9, 27, 6)
insert into fake values (4, 17, 40, 1, 20)

SELECT *,(SELECT Max(v) 
FROM (VALUES (col1), (col2), (col3), (col4) ) AS value(v))
FROM fake
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