XQuery string-join() Function

The XQuery string-join function is used to concatenate various sequences separated by a given delimiter.

Parameter explanation:

$sequence - It specifies the sequence of zero or more strings.

$delimiter - It specifies the delimiter to separate the items of above sequence.

XQuery string-join Example

Let's take an example to demonstrate the usage of XQuery string-join function. Take an XQuery expression named "courses.xqy", having the following code. It will concat all the given courses from the given XQuery expression.

XQuery Expression:

courses.xqy:

let $courses :=
<courses>
   <course>Java</course>
   <course>DotNet</course>
   <course>C/C++</course>
   <course>Oracle</course>
</courses>
return
<results>   
   <courses>{
      string-join($courses/course, ',')
   }</courses>
</results>

Create a Java based XQuery executor program to read the courses.xqy, passes it to the XQuery expression processor, and executes the expression. After that the result will be displayed.

XQueryTester.java

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.InputStream;

import javax.xml.xquery.XQConnection;
import javax.xml.xquery.XQDataSource;
import javax.xml.xquery.XQException;
import javax.xml.xquery.XQPreparedExpression;
import javax.xml.xquery.XQResultSequence;

import com.saxonica.xqj.SaxonXQDataSource;

public class XQueryTester {
   public static void main(String[] args){
      try {
         execute();
      }
      
      catch (FileNotFoundException e) {
         e.printStackTrace();
      }
      
      catch (XQException e) {
         e.printStackTrace();
      }
   }

   private static void execute() throws FileNotFoundException, XQException{
      InputStream inputStream = new FileInputStream(new File("courses.xqy"));
      XQDataSource ds = new SaxonXQDataSource();
      XQConnection conn = ds.getConnection();
      XQPreparedExpression exp = conn.prepareExpression(inputStream);
      XQResultSequence result = exp.executeQuery();
       while (result.next()) {
         System.out.println(result.getItemAsString(null));
      }
   }	
}

Execute XQuery against XML

Put the above both files to a same location. We put them on desktop in a folder name XQuery15. Compile XQueryTester.java using console. You must have JDK 1.5 or later installed on your computer and classpaths are configured.

Compile:

javac XQueryTester.java

Execute:

java XQueryTester

Output: