Package net.sf.saxon.s9api

Class XQueryExecutable

java.lang.Object

net.sf.saxon.s9api.XQueryExecutable

public class XQueryExecutable
extends Object

An XQueryExecutable represents the compiled form of a query. To execute the query, it must first be loaded to form an XQueryEvaluator.

An XQueryExecutable is immutable, and therefore thread-safe. It is simplest to load a new XQueryEvaluator each time the query is to be run. However, the XQueryEvaluator is serially reusable within a single thread.

An XQueryExecutable is created by using one of the compile methods on the XQueryCompiler class.

Since:

9.0

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	XQueryExecutable(Processor processor, XQueryExpression exp)

Method Summary

Modifier and Type	Method	Description
void	explain(Destination destination)	Produce a diagnostic representation of the compiled query, in XML form.
OccurrenceIndicator	getResultCardinality()	Get the statically-determined cardinality of the result of the query.
ItemType	getResultItemType()	Get the ItemType of the items in the result of the query, as determined by static analysis.
XQueryExpression	getUnderlyingCompiledQuery()	Get the underlying implementation object representing the compiled query.
boolean	isUpdateQuery()	Ask whether the query is an updating query: that is, whether it returns a Pending Update List rather than a Value.
XQueryEvaluator	load()	Load the query to prepare it for execution.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

XQueryExecutable

protected XQueryExecutable(Processor processor,
 XQueryExpression exp)

Method Details

load

public XQueryEvaluator load()

Load the query to prepare it for execution.

Returns:

An XQueryEvaluator. The returned XQueryEvaluator can be used to set up the dynamic context for query evaluation, and to run the query.

getResultItemType

public ItemType getResultItemType()

Get the ItemType of the items in the result of the query, as determined by static analysis. This is the most precise ItemType that the processor is able to determine from static examination of the query; the actual items in the query result are guaranteed to belong to this ItemType or to a subtype of this ItemType.

Returns:

the statically-determined ItemType of the result of the query

Since:

9.1

getResultCardinality

public OccurrenceIndicator getResultCardinality()

Get the statically-determined cardinality of the result of the query. This is the most precise cardinality that the processor is able to determine from static examination of the query.

Returns:

the statically-determined cardinality of the result of the query

Since:

9.1

isUpdateQuery

public boolean isUpdateQuery()

Ask whether the query is an updating query: that is, whether it returns a Pending Update List rather than a Value. Note that queries using the XUpdate copy-modify syntax are not considered to be updating queries.

Returns:

true if the query is an updating query, false if not

Since:

9.1

explain

public void explain(Destination destination)
             throws SaxonApiException

Produce a diagnostic representation of the compiled query, in XML form.

The detailed form of this representation is not stable (or even documented).

Parameters:

destination - the destination for the XML document containing the diagnostic representation of the compiled query

Throws:

SaxonApiException - if an error is detected

Since:

9.6

getUnderlyingCompiledQuery

public XQueryExpression getUnderlyingCompiledQuery()

Get the underlying implementation object representing the compiled query. This provides an escape hatch into lower-level APIs. The object returned by this method may change from release to release.

Returns:

the underlying implementation of the compiled query