How to insert a constructed XML nodes in XQuery? - xquery

Question

I want to insert a node using below code but if i will rerun the code i don't want my node to be repeated twice-
let $doc := fn:doc("abc.xml")
(: abc.xml looks like--
<root>
<value1>somevalue</value1>
<value2>somevalue</value2>
<value3>somevalue</value3>
<value4>somevalue</value4>
<value5>Australia</value5>
<value6>India</value6>
<value7>USA</value7>
<value8>somevalue</value8>
<value9>somevalue</value9>
<value10>somevalue</value10>
</root> :)
let $element := element Root{
element A{"A"},
element B{"B"},
element C{"C"},
element D{"D"},
element E{"E"}
}
let $doc := xdmp:node-insert-after(doc("abc.xml")//value4, $element)
return doc("abc.xml")
Whenever i am running this query my ELEMENT is getting inserted after value4 but i want that if i am running this multiple times then my element should get inserted only once and not multiple times.
Example- If i am running this 2 times-
Actual Output-
<root>
<value1>somevalue</value1>
<value2>somevalue</value2>
<value3>somevalue</value3>
<value4>somevalue</value4>
<Root>
<A>A</A>
<B>B</B>
<C>C</C>
<D>D</D>
<E>E</E>
</Root>
<Root>
<A>A</A>
<B>B</B>
<C>C</C>
<D>D</D>
<E>E</E>
</Root>
<value5>Australia</value5>
<value6>India</value6>
<value7>USA</value7>
<value8>somevalue</value8>
<value9>somevalue</value9>
<value10>somevalue</value10>
</root>
Expected Output-
<root>
<value1>somevalue</value1>
<value2>somevalue</value2>
<value3>somevalue</value3>
<value4>somevalue</value4>
<Root>
<A>A</A>
<B>B</B>
<C>C</C>
<D>D</D>
<E>E</E>
</Root>
<value5>Australia</value5>
<value6>India</value6>
<value7>USA</value7>
<value8>somevalue</value8>
<value9>somevalue</value9>
<value10>somevalue</value10>
</root>
Any Suggestions ??

Answer 1

Before inserting the node, check that it's not already there:
if (empty(child::Root)) then xdmp:update....

Answer 2

Note that you are using xdmp:node-insert-after -- this will do what the function name says (insert after) each time its called. As commented, you can conditionally call xdmp:node-update instead. Alternatively you can use xquery directly:
doc("file.xml" )/root ! <root>{ ./*[ . << ./value4] , $element , $a/value4, ./*[. >> ./value4] }</root>
Note: the "<<" operator compares "document order" (position not value)