CODEWITHSUNDEEP
xmlxquery
ilos28
ilos28

Reputation: 103

Xquery and starts-with

I have a problem with a Xquery.

I have this XML:

<peliculas>
<pelicula fechaEstreno='2007'>
    <titulo>Los Otros</titulo>
    <director>Alejandro Amenabar</director>
</pelicula>
<pelicula fechaEstreno='1986'>
    <titulo>Sangre Facil</titulo>
    <director>Ethan Coen</director>
</pelicula>
<pelicula fechaEstreno='1990'>
    <titulo>No es pais para viejos</titulo>
    <director>Ethan Coen</director>
    <director>Joel Coen</director>
</pelicula>
<pelicula fechaEstreno='2007'>
    <titulo>The Lovely Bones</titulo>
    <director>Peter Jackson</director>
</pelicula>
</peliculas>

I need to show the "titulo" where "director" starts-with 'A'. So I tried something this:

for $c in doc('C:\...\pelis.xml') //pelicula
where starts-with($c/director, 'A')
return
<pelicula>
{$c/titulo}
</pelicula>

But I have this error:

Item expected, sequence found: (element director {...}, ...).

I've used "ends-with" before and I thought the syntax it was similar for "starts-with" too, but It doesn't work.

How could I do that?

Upvotes: 2

Views: 5260

Answers (1)

Leo W&#246;rteler
Leo W&#246;rteler

Reputation: 4241

For the third pelicula element the XPath $c/director returns a sequence of two elements:

(
  <director>Ethan Coen</director>,
  <director>Joel Coen</director>
)

The function fn:starts-with(...) on the other hand expects either the empty sequence or a single item as its first argument:

fn:starts-with($arg1 as xs:string?, $arg2 as xs:string?) as xs:boolean

Here is an example of what you can do instead:

for $c in doc('C:\...\pelis.xml')//pelicula
where
    some $director in $c/director
    satisfies starts-with($director, 'A')
return <pelicula>{
    $c/titulo
}</pelicula>

Using some XPath trickery you can even make it somewhat concise:

for $c in doc('C:\...\pelis.xml')//pelicula[director[starts-with(., 'A')]]
return <pelicula>{
    $c/titulo
}</pelicula>

Upvotes: 3

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