org.ilrt.inkling.query
Class QE

java.lang.Object
  |
  +--org.ilrt.inkling.query.QE

public class QE

extends java.lang.Object

A simple, in-memory query engine implementation.
In general, it should not be used directly, but via Graph, like this:

Graph gr = new Graph(null, uri, Util.RDFXML);
gr.load();
java.sql.ResultSet r=gr.askSquish(query);

or for squish queries with 'from' clauses specifying the urls to query, use

Graph gr = new Graph();
java.sql.ResultSet r=gr.askSquish(query);


or if you want to access the query (ComplexQuery) itself, do it like this:

ComplexQuery cq=(ComplexQuery)SquishParser.parse(query);
cq.getGraphs().addElement(ug);
QE qe=new QE();

java.sql.ResultSet r=qe.executeQuery(cq);

Field Summary

java.util.Hashtable	constraints
java.util.Vector	variables

Constructor Summary

QE()

QE(java.lang.Object source, java.lang.String handler)

Method Summary

boolean	constraintCheck(TreeNode tn, Query t) constraints method - gets a constraint from a triple and returns a boolean if it matches.
void	createIndex(GraphInterface results1, Query t1)
java.sql.ResultSet	executeQuery(ComplexQuery cq) executeQuery is called with a ComplexQuery object this is basically a graph but with variables and optionally constraints and 'graphs' ('from' stuff) It returns a java.sql.Resultset.
void	fillConstraints(java.util.Vector constraints) Just puts constraints in a more useful format
java.util.Vector	listVariables(java.util.Vector triples)
java.util.Vector	listVariablesRaw(java.util.Vector triples) A list of all the variables used
static void	main(java.lang.String[] args)
GraphInterface	query(Query t, java.lang.Object source) Makes a query of an RDF database and returns the results as a graph (GraphInterface) subject-, predicate- and object- variables are the variable names.
void	toResultSet(TreeNode tn, java.util.Hashtable row) little recursive method for climbing the resultset tree

Methods inherited from class java.lang.Object

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

Field Detail

variables

public java.util.Vector variables

constraints

public java.util.Hashtable constraints

Constructor Detail

QE

public QE(java.lang.Object source,
          java.lang.String handler)

QE

public QE()

Method Detail

main

public static void main(java.lang.String[] args)

query

public GraphInterface query(Query t,
                            java.lang.Object source)

Makes a query of an RDF database and returns the results as a graph (GraphInterface) subject-, predicate- and object- variables are the variable names. subject, predicate and object can be null

createIndex

public void createIndex(GraphInterface results1,
                        Query t1)

listVariables

public java.util.Vector listVariables(java.util.Vector triples)

listVariablesRaw

public java.util.Vector listVariablesRaw(java.util.Vector triples)

A list of all the variables used

executeQuery

public java.sql.ResultSet executeQuery(ComplexQuery cq)

executeQuery is called with a ComplexQuery object this is basically a graph but with variables and optionally constraints and 'graphs' ('from' stuff) It returns a java.sql.Resultset.

toResultSet

public void toResultSet(TreeNode tn,
                        java.util.Hashtable row)

little recursive method for climbing the resultset tree

constraintCheck

public boolean constraintCheck(TreeNode tn,
                               Query t)

constraints method - gets a constraint from a triple and returns a boolean if it matches. little bit rough around the edges but seems to work ok.

fillConstraints

public void fillConstraints(java.util.Vector constraints)

Just puts constraints in a more useful format