sql-server - Sql多行合并为具有特定模式的单行

Question

Sql选择查询将多行合并为一行
使用 sqlserver 2005 及以上
我有两张 table ，即 (tb_master,tb_tasks)

create table tb_tasks(
id int IDENTITY(1,1) NOT NULL,
id_tbmaster int NOT NULL,
Tasks nvarchar(max) NOT NULL
)

create table tb_master(
id int IDENTITY(1,1) NOT NULL,
grade nchar(10) NOT NULL,
name nvarchar(50) NOT NULL,
task_date datetime NOT NULL,
)

select * from tb_master
id grade name   task_date
1  A     John   2012-02-13 10:40:00.000
2  B     Tom    2012-02-13 10:40:00.000


select tb_tasks
id  id_tbmaster  Tasks
1     1          cooking food.
2     1          Programing 2 hours
3     1          Attending meeting 
4     2          Driving car
5     2          hangout with friends

试过这个查询

select tasks + ' , ' as 'data()' from tb_tasks for xml path('')

给出输出

XML
cooking food ,  Programing 2 hours ,  Attending meeting ,  Driving car ,  hangout with friends , 

我需要像 这样的输出

id Name  grade task_date                tasksDetails
1  John   A    2012-02-13 10:40:00.000  1)cooking food, 2)Programing 2 hours, 3)Attending meeting
2  Tom    B    2012-02-13 10:40:00.000  1) Driving car, 2)hangout with friends

我试过的查询

select a.name,a.task_date,b.tasks =replace(select (CONVERT(VARCHAR,(ROW_NUMBER() OVER(ORDER BY id DESC)))) + ') ' + tasks + ' , ' as 'data()'
from tb_tasks for xml path(''))
from tb_master a inner join tb_tasks b
on a.id=b.id_tbmaster

提前致谢

Answer 1

此查询将为每个 tb_master 创建请求的事件列表。两个指针:一个应该匹配 row_number() over() 和 query 中的排序以获得一致的结果，以及 OUTER APPLY 最后一行的数字 3是分隔符中的字符数(在本例中为 ' , ')。如果您更改分隔符，则需要调整此数字。

select a.name,a.task_date, b.taskList
from tb_master a
OUTER APPLY
(
  select stuff ((select ' , '
                      + CONVERT(VARCHAR(10), ROW_NUMBER() 
                                                   OVER(ORDER BY id DESC))
                      + ') ' 
                      + tasks 
                   from tb_tasks b
                  where a.id = b.id_tbmaster
                  order by id desc
                for xml path (''))
               , 1, 3, '') taskList
) b

现场演示在 Sql Fiddle .