XQuery to display two elements data at a time? - xpath

Question

below is the xml file -
<Countries>
<Country>
<Name>India</Name>
<Capital>New Delhi</Capital>
</Country>
<Country>
<Name>USA</Name>
<Capital>Washington DC</Capital>
</Country>
<Country>
<Name>England</Name>
<Capital>London</Capital>
</Country>
<Country>
<Name>Japan</Name>
<Capital>Tokyo</Capital>
</Country>
<Country>
<Name>Srilanka</Name>
<Capital>Colombo</Capital>
</Country>
</Countries>
I have stored it in BaseX, an XMLDB. Now like plain DBs if I had stored there, I would have written simple select statement to retrieve the data from table. For example:
select name, capital from country
and got both the rows. Right? How can this be done using XQuery?

Answer 1

In a relational database (which you graphically describe as a "plain database") every query takes tables as its input and produces a table as its output. In an XML database, the input is XML and the output is XML. So you need to describe the XML you want to produce. Once you have done that, the answer to your question is yes: you can certainly write an XQuery to produce that output.

Answer 2

Seems you want a sequence of all name and capital elements:
/Countries/Country/(Name|Capital)
The result produced by this query is:
<Name>India</Name>
<Capital>New Delhi</Capital>
<Name>USA</Name>
<Capital>Washington DC</Capital>
<Name>England</Name>
<Capital>London</Capital>
<Name>Japan</Name>
<Capital>Tokyo</Capital>
<Name>Srilanka</Name>
<Capital>Colombo</Capital>

Answer 3

If you are expecting the output without elements then try this one
for $x in doc("Country")/Countries/Country
return string-join( ($x/Name, $x/Capital), " - ")
The output will be -
`India - New Delhi USA - Washington DC England - London Japan - Tokyo Srilanka - Colombo`
If you want them on separate lines then, this is what you will have to use -
for $x in doc("Country")/Countries/Country
return <li>{string-join( ($x/Name, $x/Capital), " - ")}</li>
Instead of <li> you can use any other relevant tag.