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SQLSERVER中XML查询：FORXML指定EXPLICIT(二)

2014-11-23 22:21:07 · 作者: · 浏览: 46
标签: SQLSERVER XML 查询 FORXML 指定 EXPLICIT
l as [subcategory!2!id],null as [subsubcategory!3!name!element],null as [subsubcategory!3!id!element]
union all
select 2,1,null,null,'女装',2222,null,0
union all
select 3,2,null,null,null,0,'上衣',3331
union all
select 3,2,null,null,null,0,'裤子',null
)
select * from TestXmlExplicit for xml explicit

结果：


上衣
3331


裤子



注意裤子下面的ID项不再存在，如果你想要显示具有空值的该项，需要指定elementxsinil。

指定ELEMENTXSINIL

with TestXmlExplicit
as
(
select 1 as tag,null as parent,'衣服' as [clothes!1!category],1111 as [clothes!1!id],null as [subcategory!2!name],null as [subcategory!2!id],null as [subsubcategory!3!name!element],null as [subsubcategory!3!id!ELEMENTXSINIL]
union all
select 2,1,null,null,'女装',2222,null,0
union all
select 3,2,null,null,null,0,'上衣',3331
union all
select 3,2,null,null,null,0,'裤子',null
)
select * from TestXmlExplicit for xml explicit

注意红色字体部分，最后一列指定了ELEMENTXSINIL，为了测试，把最后一行最后一列的值改为NULL。 结果：


上衣
3331


裤子




虽然裤子的id项是空值，但依然显示。

指定 ID 和 IDREF

with TestXmlExplicit
as
(
select 1 as tag,null as parent,N'LeeWhoeeUniversity' as [clothes!1!category],'011' as [clothes!1!cloid!id],'099' as [clothes!1!cloidref!idref]


)
select * from TestXmlExplicit
结果：
tag parent clothes!1!category clothes!1!cloid!id clothes!1!cloidref!idref
1 LeeWhoeeUniversity 011 099
注：上面空值项为null值，把它变成空白为了结果的清晰。
执行for xml explicit,xmldata：
with TestXmlExplicit
as
(
select 1 as tag,null as parent,N'LeeWhoeeUniversity' as [clothes!1!category],'011' as [clothes!1!cloid!id],'099' as [clothes!1!cloidref!idref]


)
select * from TestXmlExplicit for xml explicit,xmldata

红色字体为XML指定了ID和IDREF类型，通XMLDATA查看架构可知：










指定 IDREFS 指令

with TestXmlExplicit
as
(
select 1 as tag,0 as parent,null as [clothes!1!cloidlist!idrefs]
union all
select 1,0,'022'
union all
select 1,0,'025'


)
select * from TestXmlExplicit
结果集：
tag parent clothes!1!cloidlist!idrefs
1 0
1 0 022
1 0 025
注：上面空值项为null值，把它变成空白为了结果的清晰。

执行 for xml explicit,xmldata： 
with TestXmlExplicit
as
(
select 1 as tag,0 as parent,null as [clothes!1!cloidlist!idrefs]
union all
select 1,0,'022'
union all
select 1,0,'025'

)
select * from TestXmlExplicit for xml explicit,xmldata

结果： 







示例中cloidlist的类型是idrefs。IDREFS类型的元素也有多个值。因此，必须使用单独的 SELECT 子句来重复使用相同的标记、父级和键列信息。然后，ORDER BY 必须确保组成IDREFS 值的行的序列成组显示在它们的父元素下。

指定 HIDE

HIDE顾名思义，隐藏信息。 with TestXmlExplicit
as
(
select 1 as tag,null as parent,N'衣服' as [clothes!1!category],null as [subcategory!2!name],null as [subsubcategory!3!name!hide]
union all
select 2,1,null,N'女装',null
union all
select 3,2,null,null,N'上衣'
union all
select 3,2,null,null,N'裤子'
)
select * from TestXmlExplicit
结果：
tag parent clothes!1!category subcategory!2!name subsubcategory!3!name!hide
1 衣服
2 1 女装
3 2 上衣
3 2 裤子
注：上面空值项为null值，把它变成空白为了结果的清晰。

执行for xml explicit： with TestXmlExplicit
as
(
select 1 as tag,null as parent,N'衣服' as [clothes!1!category],null as [subcategory!2!name],null as [subsubcategory!3!name!hide]
union all
select 2,1,null,N'女装',null
union all
select 3,2,null,null,N'上衣'
union all
select 3,2,null,null,N'裤子'
)
select * from TestXmlExplicit for xml explicit
三级目录的subsubcategory!3!name不会显示在结果中，但是HIDE的列可以用来排序。 结果：




指定ELEMENT和XML的不同

指定ELEME