Class GroupByClausePull


  • public class GroupByClausePull
    extends TuplePull
    Represents the tuple stream delivered by an "group by" clause. This groups the tuple stream supplied as its input, and outputs a new set of tuples one per group of the input tuples. No groups are output until all the groups have been read.
    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void close()
      Close the tuple stream, indicating that although not all tuples have been read, no further tuples are required and resources can be released
      boolean nextTuple​(XPathContext context)
      Move on to the next tuple.
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    • Method Detail

      • nextTuple

        public boolean nextTuple​(XPathContext context)
                          throws XPathException
        Move on to the next tuple. Before returning, this method must set all the variables corresponding to the "returned" tuple in the local stack frame associated with the context object
        Specified by:
        nextTuple in class TuplePull
        Parameters:
        context - the dynamic evaluation context
        Returns:
        true if another tuple has been generated; false if the tuple stream is exhausted. If the method returns false, the values of the local variables corresponding to this tuple stream are undefined.
        Throws:
        XPathException - if any error occurs
      • close

        public void close()
        Close the tuple stream, indicating that although not all tuples have been read, no further tuples are required and resources can be released
        Overrides:
        close in class TuplePull