以下分別總結(jié)了sqlserver酒唉、Oracle、MySQL數(shù)據(jù)的處理SQL：
1.sqlserver:
SELECT
username,
coursename= (
STUFF(
(SELECT ',' + coursename
FROM t_user_course
WHERE username= A.username
FOR xml path('')
),1,1,''
)
)
FROM t_user_course A
GROUP by cm_pk1;
2.Oracle
(適用于oracle 12c以下版本)
select username沸移，wm_concat(to_char(coursename)) from t_user_course group by username;
(適用于oracle 12c以上版本)
select username, id, LISTAGG(subject, '-') within group(order by subject) as subject, LISTAGG(score, ',') within group(order by score) as score
from STUDENTSCORES
group by username, id
3.Mysql
select username,group_concat(coursename Separator ',') as coursename from t_user_course group by username;
