Sql server 2005 删除重复项并对模拟group_concat的结果进行排序

我已经找到了这个有趣的线索

这给了我

1   5,2,5
2   1
3   5,2,2
4   5,3

但是，我想从每次考试中删除重复项，并对连接的结果进行排序，以便

1  2,5
2  1
3  2,5
4  3,5

---

谢谢。

尝试在内部查询中使用DISTINCT，并按方法排序，而不是使用id\u检查

select 
id_exam, 
method = replace ((select distinct method AS [data()]
                   from methods
                   where id_exam = a.id_exam                      
                   order by method for xml path('')), ' ', ',')
from  methods a
where id_exam is not null
group by id_exam

---

尝试在内部查询和排序方法中使用DISTINCT而不是id\u检查

select 
id_exam, 
method = replace ((select distinct method AS [data()]
                   from methods
                   where id_exam = a.id_exam                      
                   order by method for xml path('')), ' ', ',')
from  methods a
where id_exam is not null
group by id_exam

---

将

按方法分组

添加到内部查询中，并将

按id排序检查

更改为

按方法排序

select 
id_exam, 
method = replace ((select method AS [data()]
                   from methods
                   where id_exam = a.id_exam
                   group by method                      
                   order by method for xml path('')), ' ', ',')
from  methods a
where id_exam is not null
group by id_exam

结果:

id_exam     method
----------- ---------
1           2,5
2           1
3           2,5
4           3,5

---

将

按方法分组

添加到内部查询中，并将

按id排序检查

更改为

按方法排序

select 
id_exam, 
method = replace ((select method AS [data()]
                   from methods
                   where id_exam = a.id_exam
                   group by method                      
                   order by method for xml path('')), ' ', ',')
from  methods a
where id_exam is not null
group by id_exam

结果:

id_exam     method
----------- ---------
1           2,5
2           1
3           2,5
4           3,5