将多行连接成一行

Question

我刚刚在SQL Server上学习SQL.我需要将多行连接成一列.我找了一些例子,但找不到一个我可以用来满足我需要的例子.

Country     ProjectTA   Complexity TID  Sites   Inits   Name
United States A8022 Obesity Low  4692   69  JT  AD
United States A8022 Obesity Low  4692   69  jpni    CBM Budget
United States A8022 Obesity Low  4692   69  PIHR    AD
United States A8022 Obesity Low  4692   69  jpni    CBM Budget
United States A8022 Obesity Low  4692   69  hale    ePublishing Group
United States S8033 CNS Medium   5423   69  ShyP    CBM Payment
United States S8033 CNS Medium   5423   69  dedu    ePublishing Group
United States S8033 CNS Low  5423   69  AHrp    ePublishing Group

我希望按名称连接行,并使用','列出Inits

United States A8022 Obesity Low 4692    69 JT,PIHR  AD
United States A8022 Obesity Low 4692    69 jpni, PIHR   CBM Budget
United States A8022 Obesity Low 4692    69 hale          ePublishing Group
United States S8033 CNS Medium  5423    69 ShyP          CBM Payment
United States S8033 CNS Medium  5423    69 dedu, Ahrp   ePublishing Group

任何帮助,将不胜感激.非常感谢.

Answer 1

不幸的是,SQL Server没有生成逗号分隔列表的简单功能,您必须实现FOR XML PATH才能获取列表.

有几种方法可以做到这一点,你可以使用STUFF和FOR XML PATH:

select distinct t1.country,
  t1.ProjectTA, 
  t1.Complexity,
  t1.TID,
  t1.Sites,
  STUFF(
         (SELECT ', ' + t2.Inits
          FROM yt t2
          where t1.Country = t2.Country
            and t1.ProjectTA = t2.ProjectTA
            and t1.TID = t2.TID
            and t1.Sites = t2.Sites
            and t1.name = t2.name
          FOR XML PATH (''))
          , 1, 1, '')  AS inits,
  t1.name
from yt t1;

请参阅SQL Fiddle with demo

或者您可以使用CROSS APPLY和FOR XML PATH:

select distinct t1.country,
  t1.ProjectTA, 
  t1.Complexity,
  t1.TID,
  t1.Sites, 
  left(t2.inits, len(t2.inits)-1) inits,
  t1.name
from yt t1
cross apply
(
  select t2.Inits + ', '
  from yt t2
  where t1.Country = t2.Country
    and t1.ProjectTA = t2.ProjectTA
    and t1.TID = t2.TID
    and t1.Sites = t2.Sites
    and t1.name = t2.name
  FOR XML PATH('')
) t2 (inits);

请参阅SQL Fiddle with Demo.这两者都产生了结果:

|       COUNTRY | PROJECTTA |  COMPLEXITY |  TID | SITES |      INITS |              NAME |
-------------------------------------------------------------------------------------------
| United States |     A8022 | Obesity Low | 4692 |    69 |       hale | ePublishing Group |
| United States |     A8022 | Obesity Low | 4692 |    69 | jpni, jpni |        CBM Budget |
| United States |     A8022 | Obesity Low | 4692 |    69 |   JT, PIHR |                AD |
| United States |     S8033 |     CNS Low | 5423 |    69 | dedu, AHrp | ePublishing Group |
| United States |     S8033 |  CNS Medium | 5423 |    69 | dedu, AHrp | ePublishing Group |
| United States |     S8033 |  CNS Medium | 5423 |    69 |       ShyP |       CBM Payment |