for mxl path

废话不多说，直接上例子 简单明了

create  table tb_class
(
    classId int ,
    className varchar(10)
)
go
insert into tb_class values(1,'一班')
insert into tb_class values(2,'二班')
insert into tb_class values(3,'三班')
go
create table tb_student
(
    classId int,
    stuId varchar(5),
    stuName varchar(10)
)
go
insert into tb_student values(1,'','张三')
insert into tb_student values(1,'','李四')
insert into tb_student values(1,'','王二')
insert into tb_student values(1,'','麻子')
insert into tb_student values(2,'','王尼玛')
insert into tb_student values(2,'','唐马儒')
insert into tb_student values(2,'','张全蛋')
go
select * from tb_class
select * from tb_student

1.

select stuname from tb_student for xml path

效果

<row>
  <stuname>张三</stuname>
</row>
<row>
  <stuname>李四</stuname>
</row>
<row>
  <stuname>王二</stuname>
</row>
<row>
  <stuname>麻子</stuname>
</row>
<row>
  <stuname>王尼玛</stuname>
</row>
<row>
  <stuname>唐马儒</stuname>
</row>
<row>
  <stuname>张全蛋</stuname>
</row>

2

select stuname from tb_student for xml path('')

效果

<stuname>张三</stuname>
<stuname>李四</stuname>
<stuname>王二</stuname>
<stuname>麻子</stuname>
<stuname>王尼玛</stuname>
<stuname>唐马儒</stuname>
<stuname>张全蛋</stuname>

3　　

select stuname+',' from tb_student for xml path('')

效果
张三,李四,王二,麻子,王尼玛,唐马儒,张全蛋,

4

select LEFT(stuName, LEN(stuName)-1) from (
select (
select stuname+',' from tb_student for xml path('')) as stuName ) a

张三,李四,王二,麻子,王尼玛,唐马儒,张全蛋

5

select '可以拼接字符串,'+LEFT(stuName, LEN(stuName)-1) from (
select (
select stuname+',' from tb_student for xml path('')) as stuName ) a

效果：可以拼接字符串,张三,李四,王二,麻子,王尼玛,唐马儒,张全蛋