[英]Combine two for loops and union results in XQuery
假設我們有這個文件夾
not_my_files
collections
collection1.xml
collection2.xml
collection3.xml
etc...
my_files
my_documents
mydoc1.xml
mydoc2.xml
mydoc3.xml
etc...
有xml文件的結構
collection1.xml(collection2.xml、collection3.xml 等的結構相同...)
<collection xml:id="name_of_collection_1">
<ref id="id_of_ref_1">
<title>This is title 1 of first document in this collection</title>
</ref>
<ref id="id_of_ref_2">
<title>This is title 2 of second document in this collection</title>
</ref>
</collection>
mydoc1.xml(mydoc2.xml、mydoc3.xml 等的結構相同...)
<mydoc id="my_doc_id_1">
<tag1>
<tag2>
<reference_tag>
<my_title>This is title 1 of my documents</my_title>
</reference_tag>
</tag2>
</tag1>
</mydoc>
所以:1)不同文件夾中的 xml 文件具有不同的結構和 2) ollection1.xml 可以包含許多標題,而 mydoc1.xml 只能包含 1 個時間標題。
我想從 collections/collection1.xml(等)和 my_documents/mydoc1.xml(等)中獲取所有標題。 這是一個想要的結果:
<doc>
<folder>Not my files</folder>
<title>This is title 1 of first document in this collection</title>
</doc>
<doc>
<folder>Not my files</folder>
<title>This is title 2 of second document in this collection</title>
</doc>
<doc>
<folder>My files</folder>
<title>This is title 1 of my documents</title>
</doc>
我當前的 XQuery:
xquery version "3.1";
for $doc_not_my_files in collection("/not_my_files/collections")
let $folder_not_my_files := "Not my files"
for $ref in $doc_not_my_files//ref
let $title_not_my_files := $ref/title/text()
for $doc_my_files in collection("/my_files/my_documents")
let $folder_my_files := "My files"
let $title_my_files := $doc_my_files//reference_tag/my_title/text()
return
if ($folder_my_files="My files")
then
<doc>
<folder>{$folder_my_files}</folder>
<title>{$title_my_files}</title>
</doc>
else
<doc>
<folder>{$folder_not_my_files}</folder>
<title>{$title_not_my_files}</title>
</doc>
我目前的結果:
<doc>
<folder>My files</folder>
<title>This is title 1 of my documents</title>
</doc>
<doc>
<folder>My files</folder>
<title>This is title 1 of my documents</title>
</doc>
<doc>
<folder>My files</folder>
<title>This is title 1 of my documents</title>
</doc>
<doc>
<folder>My files</folder>
<title>This is title 1 of my documents</title>
</doc>
**etc... 1000 times**
<doc>
<folder>Not my files</folder>
<title>This is title 1 of first document in this collection</title>
</doc>
<doc>
<folder>Not my files</folder>
<title>This is title 1 of first document in this collection</title>
</doc>
<doc>
<folder>Not my files</folder>
<title>This is title 1 of first document in this collection</title>
</doc>
**etc... another 1000 times**
所以,我在 XQuery 中尋找某種 SQL“UNION”替代方案......我有這種感覺,就像我有一些基本的愚蠢問題,但我是 XQuery 的新手,所以請原諒我:)
它可能與
for-each-pair(
collection("/my_files/my_documents"),
collection("/not_my_files/collections"),
function($doc, $col) {
$doc//reference_tag/my_title/text() ! <doc>
<folder>My files</folder>
<title>{.}</title>
</doc>,
$col//ref/title/text() ! <doc>
<folder>Not my files</folder>
<title>{.}</title>
</doc>
}
)
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