如何在mysql中對多列進行排序

Question

如何對多列進行排序，使排序保持條件：如果兩個人具有相同的詳細信息，則它們的排名相同。我將舉一個例子來說明：在這裏，首先排序是通過分數來完成的，如果與罰分並列，那麼如果同時存在排名，則下一個人獲得排名。

################### 
rank roll score penalty 
1 11 3  23 
2 12 3  20 
2 13 3  20 
2 14 3  20 
5 15 2  10 

所以問題是如何填充列的列？如果不可能在MySQL中是什麼其他的替代？

Answer 1

測試數據：

/* 
drop table test; 
create table test (roll int, score int, penalty int); 
insert into test (roll, score, penalty) values (11, 3, 23), (12, 3, 20), (13, 3, 20), (14,3,20), (15, 2, 10); 
*/ 

這裏說到：

ALTER TABLE test ADD COLUMN `rank` int FIRST; 
CREATE TEMPORARY TABLE tmp_test LIKE test; 
INSERT INTO tmp_test (`rank`, roll, score, penalty) 
SELECT cast(q.`rank` as unsigned integer) as `rank`, roll, score, penalty FROM (
SELECT IF(@prev != CONCAT(sq.score, '_', sq.penalty), @rownum:=@rownum2, @rownum) AS rank, 
@prev:=CONCAT(sq.score, '_', sq.penalty), 
@rownum2:=@rownum2 + 1, 
sq.* 
FROM (
    SELECT 
    roll, score, penalty 
    FROM 
    test 
    , (SELECT @rownum:=0, @prev:='', @rownum2:=1) r 
    ORDER BY score DESC, penalty DESC 
) sq 
) q; 

UPDATE test t INNER JOIN tmp_test tt ON t.roll = tt.roll AND t.score = tt.score AND t.penalty = tt.penalty 
SET t.rank = tt.rank; 
/*optionally...*/  
DROP TABLE tmp_test; 

這裏您需要使用臨時表的工作，因爲你可以」 t更新你正在閱讀的表格。會話結束後，臨時表將自動刪除。

Answer 2

試試這個：

SET @row = 0; 
select min(a.Row) as Rank, s.Roll, s.Score, s.Penalty 
from (
    select @row := @row + 1 AS Row, 
     Roll, 
     Score, 
     Penalty 
    from Score 
    order by Score desc, Penalty desc 
) a 
inner join Score s on a.Score = s.Score and a.Penalty = s.Penalty 
group by Roll, Score, Penalty 
order by min(Row)