【原地址】
for xml path作用：将多行的查询结果，根据某一些条件合并到一行。
例：现有一张表
执行下面语句
select Department,
(SELECT Employee+‘,‘ FROM People b WHERE b.Department=a.Department For XML Path(‘‘)) Student
from People as a
group by Department
得如下结果
原文：https://www.cnblogs.com/yilong-/p/8892150.html