sql 分组后把字段拼起来

2022-02-22 07:32:42

按老师的ID分类后，将对应的班级ID用 “/” 拼接起来

Sqlserver

SELECT 字段1, 
    [随便来个名字就行] = stuff(( 
        SELECT '/' + [年级2] FROM aa t 
        WHERE t.老师ID = aa.老师ID FOR xml path('')) , 1 , 1 , '') 
        FROM aa
        GROUP BY 老师ID

Mysql、Oracle

SELECT 
老师ID,
group_concat(年级ＩＤ separator '/')class,
FROM table_name 
GROUP BY 老师ＩＤ