mysql查询获取重复记录对应的数据

Question

这是一个 table 名称 test1

id  Roll Rank Grade
1    10   50   A
2    20   60   B
3    30   40   X
4    20   50   A
5    30   90   O
6    10   80   C

想要以下格式的结果：

id  Roll   Rank    Grade
1    10   50,80     A,C
2    20   60,80     B,A
3    30   40,90     X,O

Answer 1

这样做就可以了：

SELECT id, Roll, GROUP_CONCAT(Rank), GROUP_CONCAT(Grade)
FROM your_table
GROUP BY Roll
HAVING COUNT(*) > 1

Answer 2

试试这个：

SELECT A.id, A.Roll, 
       GROUP_CONCAT(A.Rank ORDER BY A.id) AS Rank, 
       GROUP_CONCAT(A.Grade ORDER BY A.id) AS Grade
FROM test1 A 
GROUP BY A.Roll
ORDER BY A.Roll;