XQuery returning an error..?

Question

Below is the XML file -

<Continents>
  <Continent n="Asia">
    <Country n="Thailand">
      <City>
        <Name>Bangkok</Name>
        <Desc>Capital on Thailand</Desc>
      </City>
    </Country>
    <Country n="India">
      <City>
        <Name>New Delhi</Name>
        <Desc>Capital on India</Desc>
      </City>
      <City>
        <Name>Mumbai</Name>
        <Desc>Financial capital on India</Desc>
      </City>
      <City>
        <Name>Chennai</Name>
        <Desc>A very good city</Desc>
      </City>
    </Country>
  </Continent>
</Continents>

Using baseX, I am writing a query to display the Name of cities containing the word Capital but is returning error. The query is -

/Continents/Continent[contains(Country/City/Desc,'Capital')]/Country/City/Name

and the error is - Error: [XPTY0004] Single item expected, (element Desc { ... }, element Desc { ... }, ...) found.

Please help me out.. Is it required to use FLWOR for such queries?

Christian Grün Christian Grün · Accepted Answer · 2012-04-25T11:43:17

Your original query could have been rewritten as follows...

/Continents/Continent[
  some $x in Country/City/Desc satisfies contains($x,'Capital')]
  /Country/City/Name

...or...

/Continents/Continent[
  for $x in Country/City/Desc
  where contains($x,'Capital')
  return $x]/Country/City/Name

...but both of the queries will return all countries of any continent that contains a city description containing 'Capital'. Instead, this is probably what you are looking for:

/Continents/Continent/Country/City[contains(Desc,'Capital')]/Name

You may as well use the contains text expression to ignore case, diacritics, etc. in your key words:

/Continents/Continent/Country/City[Desc contains text 'Capital']/Name

Hope this helps.

XQuery returning an error..?

2 Answers