CODEWITHSUNDEEP
xpath
Arcane
Arcane

Reputation: 699

Xpath - multiple tags with same name starting with a substring

I have this XML file and I need to get the name and the author/s of a book, where name of at least one author starts with "E". 

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE library SYSTEM  "knihy.dtd">
<library>
<book isbn="0470114878">
    <author hlavni="hlavni">David Hunter</author>
    <author>Jeff Rafter</author>
    <author>Joe Fawcett</author>
    <author>Eric van der Vlist</author>
    <author>Danny Ayers</author>
    <name>Beginning XML</name>
    <publisher>Wrox</publisher>
</book>
<book isbn="0596004206">
    <author>Erik Ray</author>
    <name>Learning XML</name>
    <publisher>O'Reilly</publisher>
</book>
<book isbn="0764547593">
    <author>Kay Ethier</author>
    <author>Alan Houser</author>
    <name>XML Weekend Crash Course</name>
    <year>2001</year>
</book>
<book isbn="1590596765">
    <author>Sas Jacobs</author>
    <name>Beginning XML with DOM and Ajax</name>
    <publisher>Apress</publisher>
    <year>2006</year>
</book>
</library>

I tried this approach

for $book in /library/book[starts-with(author, "E")]
return $book

but it returns XPathException in invokeTransform: A sequence of more than one item is not allowed as the first argument of starts-with() ("David Hunter", "Jeff Rafter", ...). So how can I check this sequence?

Upvotes: 2

Views: 191

Answers (1)

har07
har07

Reputation: 89285

As the error message suggests, use starts-with() in predicate for individual author elements, instead of passing all author child elements to starts-with() function at once :

for $book in /library/book[author[starts-with(., "E")]]
return $book

xpathtester demo

The above will return all books where name of at least one of the author starts with "E".

output :

<book isbn="0470114878">
    <author hlavni="hlavni">David Hunter</author>
    <author>Jeff Rafter</author>
    <author>Joe Fawcett</author>
    <author>Eric van der Vlist</author>
    <author>Danny Ayers</author>
    <name>Beginning XML</name>
    <publisher>Wrox</publisher>
</book>

<book isbn="0596004206">
    <author>Erik Ray</author>
    <name>Learning XML</name>
    <publisher>O'Reilly</publisher>
</book>

Upvotes: 3

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