SQL Server 2008 FOR XML PATH帮助

编程问答 2022-04-26

问题描述

| 我有一张历史记录表。 [添加的]一个字段具有日期时间数据类型。我要尝试的是选择一个用户20条最近的记录，然后将它们按从[添加的]字段派生的字符串分组。假设其值为
2011-05-24 03:32:57.353
，字符串为
\'Tuesday,May 24,2011\'
。我想按该字符串对记录进行分组，然后按实际时间对子节点进行排序。我还想要一些自定义XML输出。 
<ActivityHistory>
   <Actvities foo=\"Tuesday,2011\">
       <Activity id=\"10000\" bar=\"zoo\" bam=\"2011-05-24 03:32:57.353\" />
       <Activity id=\"10001\" bar=\"zoo\" bam=\"2011-05-24 03:31:57.353\" />
       <Activity id=\"10002\" bar=\"zoo\" bam=\"2011-05-24 03:28:57.353\" />
       <Activity id=\"10003\" bar=\"zoo\" bam=\"2011-05-24 03:21:57.353\" />
   </Activities>
   <Actvities foo=\"Monday,May 23,2011\">
       <Activity id=\"9990\" bar=\"zoo\" bam=\"2011-05-23 03:32:57.353\" />
       <Activity id=\"9989\" bar=\"zoo\" bam=\"2011-05-23 03:31:57.353\" />
       <Activity id=\"9988\" bar=\"zoo\" bam=\"2011-05-23 03:28:57.353\" />
       <Activity id=\"9987\" bar=\"zoo\" bam=\"2011-05-23 03:21:57.353\" />
   </Activities>
   <Actvities foo=\"Sunday,May 22,2011\">
       <Activity id=\"9900\" bar=\"zoo\" bam=\"2011-05-22 03:32:57.353\" />
       <Activity id=\"9899\" bar=\"zoo\" bam=\"2011-05-22 03:31:57.353\" />
       <Activity id=\"9898\" bar=\"zoo\" bam=\"2011-05-22 03:28:57.353\" />
       <Activity id=\"9897\" bar=\"zoo\" bam=\"2011-05-22 03:21:57.353\" />
   </Activities>
</ActivityHistory>
该有效负载将始终仅具有0-20条记录。可能永远是20。 到目前为止，我的查询看起来像这样。 
    SELECT TOP 20
     fnHistoryGroupingText(Added) [@foo]        
    FROM ActivityHistory 
WHERE MricId = 1
GROUP BY fnHistoryGroupingText(Added)
FOR XML PATH (\'Activities\'),ROOT (\'ActivityHistory\')
它生成的XML与我正在寻找的XML类似。 
<ActivityHistory>
   <Activities foo=\"Friday,May 20,2011\" />
   <Activities foo=\"Monday,2011\" />
   <Activities foo=\"Saturday,May 21,2011\" />
   <Activities foo=\"Sunday,2011\" />
   <Activities foo=\"Tuesday,2011\" />
</ActivityHistory>
请注意，它不是按日期排序的，并且没有子节点。我希望它们按时间倒序排列。我故意从查询中排除了某些字段，因为此时我正在某种程度上获得我最终想要的结构。当我介绍其他领域时，XML是遥不可及的。对文本进行分组是一个varchar，而且至今还不能很好地进行隐蔽。我可以以某种方式使用[add]字段，但是当我将其包括在查询中时，它将破坏我的分组。谁能指出我正确的方向来纠正这些问题？ [A]正确编写查询，[B]向我展示如何正确输出我要查找的XML。     

解决方法

尝试这个： 
/*  INIT  */
DECLARE @ActivityHistory TABLE (id int,bar VARCHAR(3),bam datetime)
INSERT INTO @ActivityHistory 
             SELECT  id=\'10000\',bar=\'zoo\',bam=\'2011-05-24 03:32:57\' 
       UNION SELECT  id=\'10001\',bam=\'2011-05-24 03:31:57\' 
       UNION SELECT  id=\'10002\',bam=\'2011-05-24 03:28:57\' 
       UNION SELECT  id=\'10003\',bam=\'2011-05-24 03:21:57\' 
       UNION SELECT  id= \'9990\',bam=\'2011-05-23 03:32:57\' 
       UNION SELECT  id= \'9989\',bam=\'2011-05-23 03:31:57\' 
       UNION SELECT  id= \'9988\',bam=\'2011-05-23 03:28:57\' 
       UNION SELECT  id= \'9987\',bam=\'2011-05-23 03:21:57\' 
       UNION SELECT  id= \'9900\',bam=\'2011-05-22 03:32:57\' 
       UNION SELECT  id= \'9899\',bam=\'2011-05-22 03:31:57\' 
       UNION SELECT  id= \'9898\',bam=\'2011-05-22 03:28:57\' 
       UNION SELECT  id= \'9897\',bam=\'2011-05-22 03:21:57\' 

/*  QUERY  */
;WITH 
resALL AS ( SELECT *,foo = DATENAME(weekday,bam)+\',\'+ CONVERT(VARCHAR(30),bam,107),food = CONVERT(VARCHAR(10),121) 
    FROM @ActivityHistory AS Activity
  ),resD AS ( SELECT DISTINCT foo,food FROM resALL 
  )

SELECT 
 Activities.foo,(
    SELECT id,bar,bam 
    FROM resALL AS Activity 
    WHERE foo = Activities.foo 
    ORDER BY bam desc 
    FOR XML AUTO,TYPE
   )
FROM resD AS Activities
ORDER BY Activities.food DESC
FOR XML AUTO,TYPE,ROOT (\'ActivityHistory\')

/*  OUTPUT
<ActivityHistory>
  <Activities foo=\"Tuesday,May 24,2011\">
    <Activity id=\"10000\" bar=\"zoo\" bam=\"2011-05-24T03:32:57\" />
    <Activity id=\"10001\" bar=\"zoo\" bam=\"2011-05-24T03:31:57\" />
    <Activity id=\"10002\" bar=\"zoo\" bam=\"2011-05-24T03:28:57\" />
    <Activity id=\"10003\" bar=\"zoo\" bam=\"2011-05-24T03:21:57\" />
  </Activities>
  <Activities foo=\"Monday,May 23,2011\">
    <Activity id=\"9990\" bar=\"zoo\" bam=\"2011-05-23T03:32:57\" />
    <Activity id=\"9989\" bar=\"zoo\" bam=\"2011-05-23T03:31:57\" />
    <Activity id=\"9988\" bar=\"zoo\" bam=\"2011-05-23T03:28:57\" />
    <Activity id=\"9987\" bar=\"zoo\" bam=\"2011-05-23T03:21:57\" />
  </Activities>
  <Activities foo=\"Sunday,May 22,2011\">
    <Activity id=\"9900\" bar=\"zoo\" bam=\"2011-05-22T03:32:57\" />
    <Activity id=\"9899\" bar=\"zoo\" bam=\"2011-05-22T03:31:57\" />
    <Activity id=\"9898\" bar=\"zoo\" bam=\"2011-05-22T03:28:57\" />
    <Activity id=\"9897\" bar=\"zoo\" bam=\"2011-05-22T03:21:57\" />
  </Activities>
</ActivityHistory>
*/