对多列和条件的记录进行排序

Question

I have the below table, that stores the rank of person participating in respective events.

event_running and event_jumping are the events and the ranks stored.

CREATE TABLE `ranks` (
  `id` int(11) NOT NULL,
  `personid` int(11) NOT NULL,
  `event_running` int(11) DEFAULT NULL,
  `event_longjump` int(11) DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;

Sample data

INSERT INTO `ranks` (`id`, `personid`, `event_running`, `event_longjump`) VALUES
(1, 1, 4, 8),
(2, 2, 10, 6),
(3, 3, 5, 0),
(4, 5, 20, 1),
(5, 4, 9, 3),
(6, 6, 1, 2);

SQL Fiddle Link

I want to build a leaderboard as below

| Standing | PersonID | RunningRank | JumpingRank |
|     1    |     6    |      1      |       2     |
|     2    |     4    |      9      |       3     |
|     3    |     1    |      4      |       8     |
|     4    |     3    |      5      |       0     |
|     5    |     2    |      10     |       6     |

This has to be sorted in ascending order - irrespective of the events lowest come first and also ranks above 20 are ignored.

And inputs on how can this be done?

Answer 1

you can use something similar to below

select PersonID,
       RunningRank,
       JumpingRank,
       (RunningRank + JumpingRank) as Total
from ranks
order by Total asc
limit 20;

Answer 2

Here's your query.

set @row_number = 0; 

select  (@row_number:=@row_number + 1) as standing, personid, event_running, event_longjump from ranks
where event_running < 20 and event_longjump < 20
order by 
    case when if(event_longjump=0,event_running ,event_longjump) < event_running
         then event_longjump else event_running end  

see dbfiddle

Answer 3

Your sorting criteria is a bit vague. I am assuming that you want to sort on the basis of cumulative of the ranks across all events and its jumping score.

Also, please explain the position of person Id 3 in your queation . You can do,

select PersonID,
       RunningRank,
       JumpingRank,
       (JumpingRank + RunningRank) as cumulativeRank
from ranks
ORDER BY cumulativeRank, JumpingRank aesc
limit 20;

This will get you all the positions baring person id 3