mysql中GROUP_CONCAT用法
阿新 • • 發佈:2021-06-16
語法:
group_concat([DISTINCT] 要連線的欄位 [ORDER BY 排序欄位 ASC/DESC] [Separator '分隔符'])
select teachId,studentName from bs_student
teachId | studentName |
1 | 張三 |
1 | 李四 |
1 | 張三 |
2 | 王五 |
按teachId分組,將studentName顯示在一行(預設以逗號分割)
select teachId,group_concat(studentName) as name from bs_student group by teachId
teachId |
name |
1 | 張三,李四,張三 |
2 | 王五 |
按teachId分組,將studentName顯示在一行,並對studentName去重(預設以逗號分割)
select teachId,group_concat(DISTINCT studentName) name from bs_student group by teachId
teachId |
name |
1 | 張三,李四 |
2 | 王五 |
按teachId分組,將studentName顯示在一行,並對studentName去重且倒敘排序(預設以逗號分割)
selectteachId,group_concat(DISTINCT studentName ORDER BY studentName DESC) name from bs_student group by teachId
teachId |
name |
1 | 李四,張三 |
2 | 王五 |
按teachId分組,將studentName顯示在一行,並對studentName去重且倒敘排序,並以分號分割
select teachId,group_concat(DISTINCT studentName ORDER BY studentName DESC SEPARATOR ';') name frombs_student group by teachId
teachId |
name |
1 | 李四;張三 |
2 | 王五 |