您可以借助Oracle XML DB XQuery 函数集中的XMLTable函数来实现:
select * from
XMLTable(
'
declare function local:path-to-node( $nodes as node()* ) as xs:string* {
$nodes/string-join(ancestor-or-self::*/name(.), ''/'')
};
for $i in $rdoc//name
return <ret><name_path>{local:path-to-node($i)}</name_path>{$i}</ret>
'
passing
XMLParse(content '
<users><user><name>user1</name></user>
<user><name>user2</name></user>
<group>
<user><name>user3</name></user>
</group>
<user><name>user4</name></user>
</users>'
)
as "rdoc"
columns
name_path varchar2(4000) path '//ret/name_path',
name_value varchar2(4000) path '//ret/name'
)
对我来说,XQuery 对于 XML 数据操作至少看起来比 XSLT 更直观。
您可以在此处找到有用的 XQuery 函数集。
更新 1
我想你需要在最后阶段包含完整数据的完全简单的数据集。这个目标可以通过复杂的方式实现,在下面逐步构建,但是这个变体非常耗费资源。我建议审查最终目标(选择一些特定的记录,计算元素的数量等),然后简化这个解决方案或完全改变它。
更新 2
从此更新中删除了所有步骤,除了最后一个,因为@ABCade 在评论中提出了更优雅的解决方案。此解决方案在下面的更新 3部分中提供。
第 1 步- 构建具有相应查询结果的 id 数据集
第 2 步- 聚合到单个 XML 行
第 3 步- 最后通过使用 XMLTable 查询压缩的 XML 来获得完整的纯数据集
with xmlsource as (
-- only for purpose to write long string only once
select '
<users><user><name>user1</name></user>
<user><name>user2</name></user>
<group>
<user><name>user3</name></user>
</group>
<user><name>user4</name></user>
</users>' xml_string
from dual
),
xml_table as (
-- model of xmltable
select 10 id, xml_string xml_data from xmlsource union all
select 20 id, xml_string xml_data from xmlsource union all
select 30 id, xml_string xml_data from xmlsource
)
select *
from
XMLTable(
'
for $entry_user in $full_doc/full_list/list_entry/name_info
return <tuple>
<id>{data($entry_user/../@id_value)}</id>
<path>{$entry_user/name_path/text()}</path>
<name>{$entry_user/name_value/text()}</name>
</tuple>
'
passing (
select
XMLElement("full_list",
XMLAgg(
XMLElement("list_entry",
XMLAttributes(id as "id_value"),
XMLQuery(
'
declare function local:path-to-node( $nodes as node()* ) as xs:string* {
$nodes/string-join(ancestor-or-self::*/name(.), ''/'')
};(: function to construct path :)
for $i in $rdoc//name return <name_info><name_path>{local:path-to-node($i)}</name_path><name_value>{$i/text()}</name_value></name_info>
'
passing by value XMLParse(content xml_data) as "rdoc"
returning content
)
)
)
)
from xml_table
)
as "full_doc"
columns
id_val varchar2(4000) path '//tuple/id',
path_val varchar2(4000) path '//tuple/path',
name_val varchar2(4000) path '//tuple/name'
)
更新 3
正如@ABCade 在他的评论中提到的,有很简单的方法可以将 ID 与 XQuery 结果结合起来。
因为我不喜欢答案中的外部链接,所以下面的代码代表他的 SQL fiddle,有点适应这个答案的数据源:
with xmlsource as (
-- only for purpose to write long string only once
select '
<users><user><name>user1</name></user>
<user><name>user2</name></user>
<group>
<user><name>user3</name></user>
</group>
<user><name>user4</name></user>
</users>' xml_string
from dual
),
xml_table as (
-- model of xmltable
select 10 id, xml_string xml_data from xmlsource union all
select 20 id, xml_string xml_data from xmlsource union all
select 30 id, xml_string xml_data from xmlsource
)
select xd.id, x.* from
xml_table xd,
XMLTable(
'declare function local:path-to-node( $nodes as node()* ) as xs:string* {$nodes/string-join(ancestor-or-self::*/name(.), ''/'') }; for $i in $rdoc//name return <ret><name_path>{local:path-to-node($i)}</name_path>{$i}</ret> '
passing
XMLParse(content xd.xml_data
)
as "rdoc"
columns
name_path varchar2(4000) path '//ret/name_path',
name_value varchar2(4000) path '//ret/name'
) x