source: Dev/trunk/rdfapi/dataset/DatasetDb.php @ 245

<?php
require_once RDFAPI_INCLUDE_DIR . 'dataset/Dataset.php';
require_once RDFAPI_INCLUDE_DIR . 'model/DbModel.php';
require_once RDFAPI_INCLUDE_DIR . 'dataset/IteratorFindQuadsDb.php';
// ----------------------------------------------------------------------------------
// Class: DatasetDb
// ----------------------------------------------------------------------------------

/**
* Persistent implementation of a Dataset in a database.
* A RDF dataset is a collection of named RDF graphs.
*
* @version  $Id$
* @author Daniel Westphal (http://www.d-westphal.de)
* @author Chris Bizer <chris@bizer.de>
*
* @package      dataset
* @access       public
**/
require_once(RDFAPI_INCLUDE_DIR.PACKAGE_DBASE);

class DatasetDb extends Dataset
{

        /**
        * Reference to databse connection.
        *
        * @var          resource dbConnection
        * @access       private
        */
        var $dbConnection;

        /**
        * Reference to the dbStore Object.
        *
        * @var          $dbStore dbStore
        * @access       private
        */
        var $dbStore;


        /**
        * Name of the Dataset
        *
        * @var          string
        * @access       private
        */
        var $setName;


        /**
    * Constructor
    * You can supply a Dataset name.
    *
    * @param  ADODBConnection
    * @param  DbStore
    * @param  string
        * @access       public
    */
        function DatasetDb(&$dbConnection,&$dbStore,$datasetName)
        {
                $this->dbConnection=& $dbConnection;
                $this->dbStore=&$dbStore;
                $this->setName= $datasetName;
                $this->_initialize();
        }

        /**
    * Initialize
    * Read all needed data into the set.
    *
    *
        * @access       private
    */
        function _initialize()
        {
                $recordSet =& $this->dbConnection->execute("SELECT defaultModelUri
                                         FROM datasets where datasetName='".$this->setName."'");

                $this->defaultGraph=& $this->dbStore->getModel($recordSet->fields[0]);
        }



//      === Graph level methods ========================

        /**
    * Sets the Dataset name. Return true on success, false otherwise.
    *
    * @param  string
        * @access       public
    */
        function setDatasetName($datasetName)
        {
                if ($this->dbStore->datasetExists($datasetName))
                        return false;

                $this->dbConnection->execute("UPDATE datasets SET datasetName='".$datasetName."'
                                      where datasetName='".$this->setName."'");

                $this->dbConnection->execute("UPDATE dataset_model SET datasetName='".$datasetName."'
                                      where datasetName='".$this->setName."'");
                $this->setName=$datasetName;
                return true;
        }

        /**
    * Returns the Datasets name.
    *
    * @return string
        * @access       public
    */
        function getDatasetName()
        {
                return $this->setName;
        }

        /**
         * Adds a NamedGraph to the set.
         *
         * @param NamedGraphDb
         */
        function addNamedGraph(&$graph)
        {
                $graphNameURI=$graph->getGraphName();
                $this->removeNamedGraph($graphNameURI);
                $this->dbConnection->execute('INSERT INTO dataset_model VALUES('
                  . $this->dbConnection->qstr($this->setName) . ','
                  . $this->dbConnection->qstr($graph->modelID) . ','
                  . $this->dbConnection->qstr($graphNameURI) .')');
        }


        /**
         * Overwrites the existting default graph.
         *
         * @param DbModel
         */
        function setDefaultGraph(&$graph)
        {
                $this->dbConnection->execute('UPDATE datasets SET defaultModelUri ='
                  . $this->dbConnection->qstr($graph->modelURI) . '  WHERE datasetName ='
                  . $this->dbConnection->qstr($this->setName));
        }

        /**
         * Returns a reference to the defaultGraph.
         *
         * @return NamedGraphDb
         */
        function & getDefaultGraph()
        {
                $defaultGraphURI = $this->dbConnection->GetOne("SELECT defaultModelUri FROM datasets WHERE datasetName ='".$this->setName."'");
                return ($this->dbStore->getNamedGraphDb($defaultGraphURI,'http://rdfapi-php/dataset_defaultGraph_'.$this->setName));
        }

        /**
         * Returns true, if a defaultGraph exists. False otherwise.
         *
         * @return boolean
         */
        function hasDefaultGraph()
        {
                return true;
        }

        /**
         * Removes a NamedGraph from the set. Nothing happens
         * if no graph with that name is contained in the set.
         *
         * @param string
         */
        function removeNamedGraph($graphName)
        {
                $this->dbConnection->execute('DELETE FROM dataset_model WHERE datasetName="'
                  . $this->dbConnection->qstr($this->setName) . '"  AND graphURI ="'
                  . $this->dbConnection->qstr($graphName) . '"');
        }

        /**
         * Tells wether the Dataset contains a NamedGraph.
         *
         * @param  string
         * @return boolean
         */
        function containsNamedGraph($graphName)
        {
                $count= $this->dbConnection->GetOne('SELECT count(*) FROM dataset_model WHERE datasetName="'.$this->setName.'"  AND graphURI ="'.$graphName.'"');
                return ($count>0);
        }

        /**
         * Returns the NamedGraph with a specific name from the Dataset.
         * Changes to the graph will be reflected in the set.
         *
         * @param string
         * @return NamedGraphDb or null
         */
        function &getNamedGraph($graphName)
        {
                if(!$this->containsNamedGraph($graphName))
                        return null;

                $modelVars =& $this->dbConnection->execute("SELECT models.modelURI, models.modelID, models.baseURI
                                                        FROM models, dataset_model
                                                        WHERE dataset_model.graphURI ='" .$graphName ."' AND dataset_model.modelId= models.modelID");

                return new NamedGraphDb($this->dbConnection, $modelVars->fields[0],
                                        $modelVars->fields[1], $graphName ,$modelVars->fields[2]);
        }

        /**
         * Returns the names of the namedGraphs in this set as strings in an array.
         *
         * @return Array
         */
        function listGraphNames()
        {
                $recordSet =& $this->dbConnection->execute("SELECT graphURI FROM dataset_model WHERE datasetName ='".$this->setName."'");

                $return=array();
                while (!$recordSet->EOF)
                {
                  $return[] = $recordSet->fields[0];
                  $recordSet->moveNext();
                }
                return $return;
        }

        /**
         * Creates a new NamedGraph and adds it to the set. An existing graph with the same name will be replaced. But the old namedGraph remains in the database.
         *
         * @param  string
         * @param  string
         * @return NamedGraphDb
         */
        function &createGraph($graphName,$baseURI = null)
        {
                $graph =& $this->dbStore->getNewNamedGraphDb(uniqid('http://rdfapi-php/namedGraph_'),$graphName,$baseURI);
                $this->addNamedGraph($graph);

                return $graph;
        }

        /**
         * Deletes all NamedGraphs from the set.
         */
        function clear()
        {
                $this->dbConnection->execute("DELETE FROM dataset_model WHERE datasetName ='".$this->setName."'");
        }

        /**
         * Returns the number of NamedGraphs in the set. Empty graphs are counted.
         *
         * @return int
         */
        function countGraphs()
        {
                return ($this->dbConnection->GetOne("SELECT count(*) FROM dataset_model WHERE datasetName ='".$this->setName."'"));
        }

        /**
         * Returns an iterator over all {@link NamedGraph}s in the set.
         *
         * @return IteratorAllGraphsDb
         */
        function &listNamedGraphs()
        {
                $recordSet =& $this->dbConnection->execute("SELECT graphURI FROM dataset_model WHERE datasetName ='".$this->setName."'");
                $it = new IteratorAllGraphsDb($recordSet, $this);
                return $it;
        }

        /**
         * Tells wether the set contains any NamedGraphs.
         *
         * @return boolean
         */
        function isEmpty()
        {
                return ($this->countGraphs()==0);
        }

        /**
         * Add all named graphs of the other dataset to this dataset.
         *
         * @param Dataset
         */
        function addAll($otherDataset)
        {
                for($iterator = $otherDataset->listNamedGraphs(); $iterator->valid(); $iterator->next())
                {
                        $this->addNamedGraph($iterator->current());
                };

                if ($otherDataset->hasDefaultGraph())
                {
                        $this->defaultGraph = $this->defaultGraph->unite($otherDataset->getDefaultGraph());
                }
        }

//      === Quad level methods ========================

        /**
         * Adds a quad to the Dataset. The argument must not contain any
         * wildcards. If the quad is already present, nothing happens. A new
         * named graph will automatically be created if necessary.
         *
         * @param Quad
         */
        function addQuad(&$quad)
        {
                $graphName=$quad->getGraphName();
                $graphName=$graphName->getLabel();

                $graph=& $this->getNamedGraph($graphName);

                if ($graph===null)
                        $graph=& $this->createGraph($graphName);

                $statement=$quad->getStatement();
                $graph->add($statement);
        }

        /**
         * Tells wether the Dataset contains a quad or
         * quads matching a pattern.
         *
         * @param Resource
         * @param Resource
         * @param Resource
         * @param Resource
         * @return boolean
         */
        function containsQuad($graphName,$subject,$predicate,$object)
        {
                // static part of the sql statement
                $sql = "SELECT count(*)
                        FROM statements, dataset_model
                        WHERE datasetName ='".$this->setName."' AND statements.modelID=dataset_model.modelId ";

                if($graphName!=null)
                {
                        $sql.= " AND graphURI ='".$graphName->getLabel()."'";
                }

                // dynamic part of the sql statement
                $sql .= DbModel::_createDynSqlPart_SPO($subject, $predicate, $object);

                return (($this->dbConnection->GetOne($sql))>0);
        }

        /**
         * Deletes a Quad from the RDF dataset.
         *
         * @param Quad
         */
        function removeQuad($quad)
        {
                $graphName=$quad->getGraphName();$graphName=$graphName->getLabel();
                //find namedGraph IDs
                $graphID = $this->dbConnection->GetOne("SELECT modelId FROM dataset_model WHERE graphURI ='$graphName'");

                // static part of the sql statement
                $sql = "DELETE FROM statements WHERE modelID = $graphID";

                // dynamic part of the sql statement
                $sql .= DbModel::_createDynSqlPart_SPO($quad->getSubject(), $quad->getPredicate(), $quad->getObject());

                // execute the query
                if($graphID)
                        $recordSet =& $this->dbConnection->execute($sql);
        }

        /**
         * Counts the Quads in the RDF dataset. Identical Triples in
         * different NamedGraphs are counted individually.
         *
         * @return int
         */
        function countQuads()
        {
                $sql = "SELECT count(*)
                        FROM statements, dataset_model
                        WHERE datasetName ='".$this->setName."' AND statements.modelID=dataset_model.modelId ";

                return ((int)$this->dbConnection->GetOne($sql));
        }

        /**
         * Finds Statements that match a quad pattern. The argument may contain
         * wildcards.
         *
         * @param Resource or null
         * @param Resource or null
         * @param Resource or null
         * @param Resource or null
         * @return IteratorFindQuadsDb
         */
        function &findInNamedGraphs($graphName,$subject,$predicate,$object,$returnAsTriples =false )
        {
                // static part of the sql statement
                $sql = "SELECT subject, predicate, object, l_language, l_datatype, subject_is, object_is, dataset_model.graphURI
                        FROM statements, dataset_model
                        WHERE datasetName ='".$this->setName."' AND statements.modelID=dataset_model.modelId ";

                if($graphName!=null)
                {
                        $sql.= " AND graphURI ='".$graphName->getLabel()."'";
                }

                // dynamic part of the sql statement
                $sql .= DbModel::_createDynSqlPart_SPO($subject, $predicate, $object);

                // execute the query
                $recordSet =& $this->dbConnection->execute($sql);


                $it = new IteratorFindQuadsDb($recordSet, $this, $returnAsTriples);
                return $it;
        }

        /**
         * Finds Statements that match a pattern in the default Graph. The argument may contain
         * wildcards.
         *
         * @param Resource or null
         * @param Resource or null
         * @param Resource or null
         * @return IteratorFindQuadsDb
         */
        function &findInDefaultGraph($subject,$predicate,$object)
        {
                $defaultGraphID = (int)$this->dbConnection->GetOne("SELECT models.modelID FROM datasets, models WHERE datasets.datasetName ='".$this->setName."' AND datasets.defaultModelUri = models.modelURI");
                // static part of the sql statement
                $sql = "SELECT subject, predicate, object, l_language, l_datatype, subject_is, object_is
                        FROM statements
                        WHERE modelID ='$defaultGraphID'";

                // dynamic part of the sql statement
                $sql .= DbModel::_createDynSqlPart_SPO($subject, $predicate, $object);

                // execute the query
                $recordSet =& $this->dbConnection->execute($sql);

                $it = new IteratorFindQuadsDb($recordSet, $this, true);
                return $it;
        }
}
?>