将一行中的多行结果分组在一列

Question

以下查询给出了两个结果，其中除最后一列v2_roles.id外，所有内容都相同。有没有办法将它们分组在一列（可以是逗号seprated列表），得到的只是一个结果回

SELECT v2_admin.adminid, 
     v2_admin.adminname, 
     v2_admin.login, 
     v2_admin.email, 
     v2_roles.id 
FROM v2_admin 
     INNER JOIN v2_admin_roles 
       ON v2_admin.adminid = v2_admin_roles.adminid 
     INNER JOIN v2_roles 
       ON v2_admin_roles.roleid = v2_roles.id 
WHERE v2_admin.adminid = 2 

Answer 1

这也应该工作，

;WITH mytable AS (
    SELECT v2_admin.adminid, 
     v2_admin.adminname, 
     v2_admin.login, 
     v2_admin.email, 
     v2_roles.id 
    FROM v2_admin 
     INNER JOIN v2_admin_roles 
       ON v2_admin.adminid = v2_admin_roles.adminid 
     INNER JOIN v2_roles 
       ON v2_admin_roles.roleid = v2_roles.id 
    WHERE v2_admin.adminid = 2 
) 

SELECT t1.adminid,t1.adminname, t1.login, t1.email, 
     roleIds =REPLACE((SELECT convert(varchar,id) AS [data()] 
       FROM mytable t2 
       WHERE t2.adminid = t1.adminid 
       --ORDER BY t2.adminid 
       FOR XML PATH('') 
      ), ' ', ' , ') 
FROM mytable t1 
GROUP BY t1.adminid,t1.adminname, t1.login, t1.email ; 

Answer 2

这是使用FOR XML到外地转换到一个列表的小动作和STUFF删除开始逗号 - 这应该是接近（未经测试）：

SELECT v2_admin.adminid, 
     v2_admin.adminname, 
     v2_admin.login, 
     v2_admin.email, 
     STUFF(
     (
      SELECT ',' + CAST(v2_roles.id as varchar) AS [text()] 
       FROM v2_roles 
       WHERE v2_admin_roles.roleid = v2_roles.id 
      ORDER BY v2_roles.id 
      FOR XML PATH('') 
     ), 1, 1, '') AS Roles 
FROM v2_admin 
     INNER JOIN v2_admin_roles 
       ON v2_admin.adminid = v2_admin_roles.adminid 
WHERE v2_admin.adminid = 2 
GROUP BY v2_admin.adminid, 
     v2_admin.adminname, 
     v2_admin.login, 
     v2_admin.email